1666415520 has 864 divisors, whose sum is σ = 7663481280. Its totient is φ = 325140480.

The previous prime is 1666415519. The next prime is 1666415537. The reversal of 1666415520 is 255146661.

1666415520 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 14746984 + ... + 14747096.

It is an arithmetic number, because the mean of its divisors is an integer number (8869770).

Almost surely, 2^1666415520 is an apocalyptic number.

1666415520 is a gapful number since it is divisible by the number (10) 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 1666415520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3831740640).

1666415520 is an abundant number, since it is smaller than the sum of its proper divisors (5997065760).

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

1666415520 is a wasteful number, since it uses less digits than its factorization.

1666415520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 1666415520 is about 40821.7530245824. The cubic root of 1666415520 is about 1185.5715450453.

The spelling of 1666415520 in words is "one billion, six hundred sixty-six million, four hundred fifteen thousand, five hundred twenty".