21161110344 has 64 divisors (see below), whose sum is σ = 58283599680. Its totient is φ = 6348960000.

The previous prime is 21161110339. The next prime is 21161110351. The reversal of 21161110344 is 44301116112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 370147 + ... + 423474.

It is an arithmetic number, because the mean of its divisors is an integer number (910681245).

Almost surely, 2^21161110344 is an apocalyptic number.

21161110344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21161110344 is an abundant number, since it is smaller than the sum of its proper divisors (37122489336).

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

21161110344 is a wasteful number, since it uses less digits than its factorization.

21161110344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793742 (or 793738 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

Adding to 21161110344 its reverse (44301116112), we get a palindrome (65462226456).

The spelling of 21161110344 in words is "twenty-one billion, one hundred sixty-one million, one hundred ten thousand, three hundred forty-four".