21357262172 has 24 divisors (see below), whose sum is σ = 38168046672. Its totient is φ = 10453766400.

The previous prime is 21357262133. The next prime is 21357262177. The reversal of 21357262172 is 27126275312.

It is a super-2 number, since 2×21357262172² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357262177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155933 + ... + 258900.

It is an arithmetic number, because the mean of its divisors is an integer number (1590335278).

Almost surely, 2^21357262172 is an apocalyptic number.

It is an amenable number.

21357262172 is a deficient number, since it is larger than the sum of its proper divisors (16810784500).

21357262172 is a wasteful number, since it uses less digits than its factorization.

21357262172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415109 (or 415107 counting only the distinct ones).

The product of its digits is 70560, while the sum is 38.

The spelling of 21357262172 in words is "twenty-one billion, three hundred fifty-seven million, two hundred sixty-two thousand, one hundred seventy-two".