21004131024 has 60 divisors (see below), whose sum is σ = 61338160416. Its totient is φ = 6696968256.

The previous prime is 21004131017. The next prime is 21004131041. The reversal of 21004131024 is 42013140012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21004130988 and 21004131006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3167602 + ... + 3174225.

Almost surely, 2^21004131024 is an apocalyptic number.

21004131024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21004131024 is an abundant number, since it is smaller than the sum of its proper divisors (40334029392).

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

21004131024 is a wasteful number, since it uses less digits than its factorization.

21004131024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6341864 (or 6341855 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21004131024 its reverse (42013140012), we get a palindrome (63017271036).

The spelling of 21004131024 in words is "twenty-one billion, four million, one hundred thirty-one thousand, twenty-four".