16640646 has 24 divisors (see below), whose sum is σ = 36583512. Its totient is φ = 5042400.

The previous prime is 16640621. The next prime is 16640647. The reversal of 16640646 is 64604661.

It is a super-2 number, since 2×16640646² = 553822198594632, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16640647) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10735 + ... + 12186.

It is an arithmetic number, because the mean of its divisors is an integer number (1524313).

Almost surely, 2^16640646 is an apocalyptic number.

16640646 is an abundant number, since it is smaller than the sum of its proper divisors (19942866).

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

16640646 is a wasteful number, since it uses less digits than its factorization.

16640646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22948 (or 22937 counting only the distinct ones).

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

The square root of 16640646 is about 4079.2947919953. The cubic root of 16640646 is about 255.3034756759.

The spelling of 16640646 in words is "sixteen million, six hundred forty thousand, six hundred forty-six".