21112203504 has 60 divisors (see below), whose sum is σ = 63444332904. Its totient is φ = 6032057472.

The previous prime is 21112203503. The next prime is 21112203643. The reversal of 21112203504 is 40530221112.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112203503) 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, 4485787 + ... + 4490490.

Almost surely, 2^21112203504 is an apocalyptic number.

21112203504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21112203504 is an abundant number, since it is smaller than the sum of its proper divisors (42332129400).

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

21112203504 is a wasteful number, since it uses less digits than its factorization.

21112203504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8976302 (or 8976289 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21112203504 its reverse (40530221112), we get a palindrome (61642424616).

The spelling of 21112203504 in words is "twenty-one billion, one hundred twelve million, two hundred three thousand, five hundred four".