664916280 has 96 divisors (see below), whose sum is σ = 2320442640. Its totient is φ = 151979520.

The previous prime is 664916261. The next prime is 664916281. The reversal of 664916280 is 82619466.

It is a super-2 number, since 2×664916280² = 884227318818076800, which contains 22 as substring.

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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664916281) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50661 + ... + 62420.

Almost surely, 2^664916280 is an apocalyptic number.

664916280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664916280 is an abundant number, since it is smaller than the sum of its proper divisors (1655526360).

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

664916280 is a wasteful number, since it uses less digits than its factorization.

664916280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113109 (or 113098 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 664916280 is about 25785.9706041871. The cubic root of 664916280 is about 872.8152428291.

It can be divided in two parts, 66491 and 6280, that added together give a triangular number (72771 = T₃₈₁).

The spelling of 664916280 in words is "six hundred sixty-four million, nine hundred sixteen thousand, two hundred eighty".