21022655520 has 192 divisors, whose sum is σ = 66879074304. Its totient is φ = 5550673920.

The previous prime is 21022655501. The next prime is 21022655543. The reversal of 21022655520 is 2555622012.

It is a super-2 number, since 2×21022655520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31803990 + ... + 31804650.

It is an arithmetic number, because the mean of its divisors is an integer number (348328512).

Almost surely, 2^21022655520 is an apocalyptic number.

21022655520 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 21022655520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33439537152).

21022655520 is an abundant number, since it is smaller than the sum of its proper divisors (45856418784).

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

21022655520 is a wasteful number, since it uses less digits than its factorization.

21022655520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235 (or 1227 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The spelling of 21022655520 in words is "twenty-one billion, twenty-two million, six hundred fifty-five thousand, five hundred twenty".