21113000400 has 120 divisors (see below), whose sum is σ = 71610398784. Its totient is φ = 5298944000.

The previous prime is 21113000369. The next prime is 21113000401. The reversal of 21113000400 is 400031112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113000401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 497076 + ... + 537875.

Almost surely, 2^21113000400 is an apocalyptic number.

21113000400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113000400 is an abundant number, since it is smaller than the sum of its proper divisors (50497398384).

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

21113000400 is a wasteful number, since it uses less digits than its factorization.

21113000400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034989 (or 1034978 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21113000400 its reverse (400031112), we get a palindrome (21513031512).

The spelling of 21113000400 in words is "twenty-one billion, one hundred thirteen million, four hundred", and thus it is an aban number.