21161635224 has 64 divisors (see below), whose sum is σ = 56150236800. Its totient is φ = 6623046144.

The previous prime is 21161635217. The next prime is 21161635237. The reversal of 21161635224 is 42253616112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109059 + ... + 232845.

It is an arithmetic number, because the mean of its divisors is an integer number (877347450).

Almost surely, 2^21161635224 is an apocalyptic number.

21161635224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21161635224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28075118400).

21161635224 is an abundant number, since it is smaller than the sum of its proper divisors (34988601576).

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

21161635224 is a wasteful number, since it uses less digits than its factorization.

21161635224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124232 (or 124228 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The spelling of 21161635224 in words is "twenty-one billion, one hundred sixty-one million, six hundred thirty-five thousand, two hundred twenty-four".