21510023412 has 48 divisors (see below), whose sum is σ = 51430579200. Its totient is φ = 6994646880.

The previous prime is 21510023411. The next prime is 21510023419. The reversal of 21510023412 is 21432001512.

It is a super-2 number, since 2×21510023412² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21510023411) 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, 23212 + ... + 208707.

It is an arithmetic number, because the mean of its divisors is an integer number (1071470400).

Almost surely, 2^21510023412 is an apocalyptic number.

It is an amenable number.

21510023412 is an abundant number, since it is smaller than the sum of its proper divisors (29920555788).

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

21510023412 is a wasteful number, since it uses less digits than its factorization.

21510023412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232116 (or 232114 counting only the distinct ones).

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

Adding to 21510023412 its reverse (21432001512), we get a palindrome (42942024924).

The spelling of 21510023412 in words is "twenty-one billion, five hundred ten million, twenty-three thousand, four hundred twelve".