16620621 has 16 divisors (see below), whose sum is σ = 22868160. Its totient is φ = 10730880.

The previous prime is 16620601. The next prime is 16620671. The reversal of 16620621 is 12602661.

It is not a de Polignac number, because 16620621 - 2⁷ = 16620493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16620591 and 16620600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16620601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19635 + ... + 20463.

It is an arithmetic number, because the mean of its divisors is an integer number (1429260).

Almost surely, 2^16620621 is an apocalyptic number.

It is an amenable number.

16620621 is a deficient number, since it is larger than the sum of its proper divisors (6247539).

16620621 is a wasteful number, since it uses less digits than its factorization.

16620621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1036.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 16620621 is about 4076.8395847764. The cubic root of 16620621 is about 255.2010256426.

The spelling of 16620621 in words is "sixteen million, six hundred twenty thousand, six hundred twenty-one".