21312120004 has 12 divisors (see below), whose sum is σ = 42624240064. Its totient is φ = 9133765704.

The previous prime is 21312119993. The next prime is 21312120029. The reversal of 21312120004 is 40002121312.

21312120004 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21312120004.

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, 380573544 + ... + 380573599.

Almost surely, 2^21312120004 is an apocalyptic number.

It is an amenable number.

21312120004 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21312120004 is a wasteful number, since it uses less digits than its factorization.

21312120004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761147154 (or 761147152 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21312120004 its reverse (40002121312), we get a palindrome (61314241316).

The spelling of 21312120004 in words is "twenty-one billion, three hundred twelve million, one hundred twenty thousand, four".