21312034040 has 64 divisors (see below), whose sum is σ = 53725217760. Its totient is φ = 7540369920.

The previous prime is 21312033961. The next prime is 21312034043. The reversal of 21312034040 is 4043021312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312034043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 638267 + ... + 670826.

Almost surely, 2^21312034040 is an apocalyptic number.

21312034040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312034040 is an abundant number, since it is smaller than the sum of its proper divisors (32413183720).

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

21312034040 is a wasteful number, since it uses less digits than its factorization.

21312034040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309152 (or 1309148 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21312034040 its reverse (4043021312), we get a palindrome (25355055352).

The spelling of 21312034040 in words is "twenty-one billion, three hundred twelve million, thirty-four thousand, forty".