21105633400 has 48 divisors (see below), whose sum is σ = 49902330600. Its totient is φ = 8299159680.

The previous prime is 21105633383. The next prime is 21105633401. The reversal of 21105633400 is 433650112.

It is a super-2 number, since 2×21105633400² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105633401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 882507 + ... + 906106.

Almost surely, 2^21105633400 is an apocalyptic number.

21105633400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21105633400 is an abundant number, since it is smaller than the sum of its proper divisors (28796697200).

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

21105633400 is a wasteful number, since it uses less digits than its factorization.

21105633400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1788688 (or 1788679 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The spelling of 21105633400 in words is "twenty-one billion, one hundred five million, six hundred thirty-three thousand, four hundred".