16640625 has 32 divisors (see below), whose sum is σ = 28124928. Its totient is φ = 8750000.

The previous prime is 16640621. The next prime is 16640647. The reversal of 16640625 is 52604661.

It is not a de Polignac number, because 16640625 - 2² = 16640621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16640592 and 16640601.

It is not an unprimeable number, because it can be changed into a prime (16640621) 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, 234340 + ... + 234410.

It is an arithmetic number, because the mean of its divisors is an integer number (878904).

Almost surely, 2^16640625 is an apocalyptic number.

16640625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16640625 is a deficient number, since it is larger than the sum of its proper divisors (11484303).

16640625 is an frugal number, since it uses more digits than its factorization.

16640625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 16640625 is about 4079.2922180202. The cubic root of 16640625 is about 255.3033682807.

The spelling of 16640625 in words is "sixteen million, six hundred forty thousand, six hundred twenty-five".