1668016890 has 24 divisors (see below), whose sum is σ = 4336844148. Its totient is φ = 444804480.

The previous prime is 1668016873. The next prime is 1668016967. The reversal of 1668016890 is 986108661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1571250321 + 96766569 = 39639^2 + 9837^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9266671 + ... + 9266850.

Almost surely, 2^1668016890 is an apocalyptic number.

1668016890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1668016890 is an abundant number, since it is smaller than the sum of its proper divisors (2668827258).

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

1668016890 is a wasteful number, since it uses less digits than its factorization.

1668016890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18533534 (or 18533531 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 1668016890 is about 40841.3624895155. The cubic root of 1668016890 is about 1185.9511884301.

The spelling of 1668016890 in words is "one billion, six hundred sixty-eight million, sixteen thousand, eight hundred ninety".