21676920 has 64 divisors (see below), whose sum is σ = 67284000. Its totient is φ = 5580288.

The previous prime is 21676909. The next prime is 21676927. The reversal of 21676920 is 2967612.

21676920 is nontrivially palindromic in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21676927) 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, 366 + ... + 6594.

Almost surely, 2^21676920 is an apocalyptic number.

21676920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21676920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33642000).

21676920 is an abundant number, since it is smaller than the sum of its proper divisors (45607080).

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

21676920 is a wasteful number, since it uses less digits than its factorization.

21676920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6272 (or 6268 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 21676920 is about 4655.8479356611. The cubic root of 21676920 is about 278.8255226469.

The spelling of 21676920 in words is "twenty-one million, six hundred seventy-six thousand, nine hundred twenty".