21620654 has 16 divisors (see below), whose sum is σ = 36336816. Its totient is φ = 9561600.

The previous prime is 21620603. The next prime is 21620659. The reversal of 21620654 is 45602612.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12467 + ... + 14094.

It is an arithmetic number, because the mean of its divisors is an integer number (2271051).

Almost surely, 2^21620654 is an apocalyptic number.

21620654 is a deficient number, since it is larger than the sum of its proper divisors (14716162).

21620654 is a wasteful number, since it uses less digits than its factorization.

21620654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26611.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 21620654 is about 4649.8015011396. The cubic root of 21620654 is about 278.5840678276.

The spelling of 21620654 in words is "twenty-one million, six hundred twenty thousand, six hundred fifty-four".