21013112164 has 18 divisors (see below), whose sum is σ = 40419850982. Its totient is φ = 9551414400.

The previous prime is 21013112083. The next prime is 21013112167. The reversal of 21013112164 is 46121131012.

It can be written as a sum of positive squares in only one way, i.e., 14614392100 + 6398720064 = 120890^2 + 79992^2 .

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21013112167) 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 5 ways as a sum of consecutive naturals, for example, 21707277 + ... + 21708244.

Almost surely, 2^21013112164 is an apocalyptic number.

It is an amenable number.

21013112164 is a deficient number, since it is larger than the sum of its proper divisors (19406738818).

21013112164 is a wasteful number, since it uses less digits than its factorization.

21013112164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43415547 (or 43415534 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21013112164 its reverse (46121131012), we get a palindrome (67134243176).

The spelling of 21013112164 in words is "twenty-one billion, thirteen million, one hundred twelve thousand, one hundred sixty-four".