21656227320 has 384 divisors, whose sum is σ = 88053114240. Its totient is φ = 4493905920.

The previous prime is 21656227301. The next prime is 21656227357. The reversal of 21656227320 is 2372265612.

21656227320 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 622 + 7 + 3 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1992942 + ... + 2003778.

It is an arithmetic number, because the mean of its divisors is an integer number (229304985).

Almost surely, 2^21656227320 is an apocalyptic number.

21656227320 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 21656227320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44026557120).

21656227320 is an abundant number, since it is smaller than the sum of its proper divisors (66396886920).

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

21656227320 is a wasteful number, since it uses less digits than its factorization.

21656227320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10935 (or 10928 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The spelling of 21656227320 in words is "twenty-one billion, six hundred fifty-six million, two hundred twenty-seven thousand, three hundred twenty".