1668520392 has 128 divisors (see below), whose sum is σ = 5221877760. Its totient is φ = 431608320.

The previous prime is 1668520391. The next prime is 1668520393. The reversal of 1668520392 is 2930258661.

1668520392 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1668520391) and next prime (1668520393).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (1668520391) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 484308 + ... + 487740.

It is an arithmetic number, because the mean of its divisors is an integer number (40795920).

Almost surely, 2^1668520392 is an apocalyptic number.

1668520392 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1668520392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2610938880).

1668520392 is an abundant number, since it is smaller than the sum of its proper divisors (3553357368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1668520392 is a wasteful number, since it uses less digits than its factorization.

1668520392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3723 (or 3719 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 1668520392 is about 40847.5261429624. The cubic root of 1668520392 is about 1186.0705055118.

The spelling of 1668520392 in words is "one billion, six hundred sixty-eight million, five hundred twenty thousand, three hundred ninety-two".