21957397710 has 128 divisors (see below), whose sum is σ = 56982320640. Its totient is φ = 5395009536.

The previous prime is 21957397687. The next prime is 21957397711. The reversal of 21957397710 is 1779375912.

It is a super-2 number, since 2×21957397710² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21957397711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5172849 + ... + 5177091.

It is an arithmetic number, because the mean of its divisors is an integer number (445174380).

Almost surely, 2^21957397710 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21957397710, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28491160320).

21957397710 is an abundant number, since it is smaller than the sum of its proper divisors (35024922930).

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

21957397710 is a wasteful number, since it uses less digits than its factorization.

21957397710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4482.

The product of its (nonzero) digits is 833490, while the sum is 51.

The spelling of 21957397710 in words is "twenty-one billion, nine hundred fifty-seven million, three hundred ninety-seven thousand, seven hundred ten".