21240431024 has 20 divisors (see below), whose sum is σ = 42572416560. Its totient is φ = 10254000960.

The previous prime is 21240430987. The next prime is 21240431039. The reversal of 21240431024 is 42013404212.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22887932 + ... + 22888859.

It is an arithmetic number, because the mean of its divisors is an integer number (2128620828).

Almost surely, 2^21240431024 is an apocalyptic number.

It is an amenable number.

21240431024 is an abundant number, since it is smaller than the sum of its proper divisors (21331985536).

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

21240431024 is a wasteful number, since it uses less digits than its factorization.

21240431024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45776828 (or 45776822 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21240431024 its reverse (42013404212), we get a palindrome (63253835236).

The spelling of 21240431024 in words is "twenty-one billion, two hundred forty million, four hundred thirty-one thousand, twenty-four".