21880628 has 48 divisors (see below), whose sum is σ = 50265600. Its totient is φ = 8074080.

The previous prime is 21880591. The next prime is 21880643. The reversal of 21880628 is 82608812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3983 + ... + 7721.

It is an arithmetic number, because the mean of its divisors is an integer number (1047200).

Almost surely, 2^21880628 is an apocalyptic number.

21880628 is a gapful number since it is divisible by the number (28) 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 21880628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25132800).

21880628 is an abundant number, since it is smaller than the sum of its proper divisors (28384972).

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

21880628 is a wasteful number, since it uses less digits than its factorization.

21880628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3780 (or 3778 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 21880628 is about 4677.6733532815. The cubic root of 21880628 is about 279.6962181546.

The spelling of 21880628 in words is "twenty-one million, eight hundred eighty thousand, six hundred twenty-eight".