21620454 has 16 divisors (see below), whose sum is σ = 44636160. Its totient is φ = 6974280.

The previous prime is 21620453. The next prime is 21620471. The reversal of 21620454 is 45402612.

It is a super-2 number, since 2×21620454² = 934888062332232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620453) 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, 57934 + ... + 58305.

It is an arithmetic number, because the mean of its divisors is an integer number (2789760).

Almost surely, 2^21620454 is an apocalyptic number.

21620454 is an abundant number, since it is smaller than the sum of its proper divisors (23015706).

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

21620454 is a wasteful number, since it uses less digits than its factorization.

21620454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116275.

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 21620454 is about 4649.7799947955. The cubic root of 21620454 is about 278.5832088190.

The spelling of 21620454 in words is "twenty-one million, six hundred twenty thousand, four hundred fifty-four".