16664640 has 56 divisors (see below), whose sum is σ = 52913280. Its totient is φ = 4443648.

The previous prime is 16664629. The next prime is 16664663. The reversal of 16664640 is 4646661.

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7720 + ... + 9639.

It is an arithmetic number, because the mean of its divisors is an integer number (944880).

Almost surely, 2^16664640 is an apocalyptic number.

16664640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16664640 is an abundant number, since it is smaller than the sum of its proper divisors (36248640).

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

16664640 is a wasteful number, since it uses less digits than its factorization.

16664640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17379 (or 17369 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 16664640 is about 4082.2346821318. The cubic root of 16664640 is about 255.4261233529.

The spelling of 16664640 in words is "sixteen million, six hundred sixty-four thousand, six hundred forty".