21357422780 has 24 divisors (see below), whose sum is σ = 45136267008. Its totient is φ = 8488554048.

The previous prime is 21357422761. The next prime is 21357422783. The reversal of 21357422780 is 8722475312.

It is a super-2 number, since 2×21357422780² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357422783) 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, 3397724 + ... + 3404003.

It is an arithmetic number, because the mean of its divisors is an integer number (1880677792).

Almost surely, 2^21357422780 is an apocalyptic number.

21357422780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21357422780 is an abundant number, since it is smaller than the sum of its proper divisors (23778844228).

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

21357422780 is a wasteful number, since it uses less digits than its factorization.

21357422780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6801893 (or 6801891 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 41.

The spelling of 21357422780 in words is "twenty-one billion, three hundred fifty-seven million, four hundred twenty-two thousand, seven hundred eighty".