21520506412 has 12 divisors (see below), whose sum is σ = 38959537680. Its totient is φ = 10389209936.

The previous prime is 21520506409. The next prime is 21520506467. The reversal of 21520506412 is 21460502512.

It is a super-2 number, since 2×21520506412² (a number of 21 digits) contains 22 as substring.

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, 92760688 + ... + 92760919.

It is an arithmetic number, because the mean of its divisors is an integer number (3246628140).

Almost surely, 2^21520506412 is an apocalyptic number.

It is an amenable number.

21520506412 is a deficient number, since it is larger than the sum of its proper divisors (17439031268).

21520506412 is a wasteful number, since it uses less digits than its factorization.

21520506412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185521640 (or 185521638 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The spelling of 21520506412 in words is "twenty-one billion, five hundred twenty million, five hundred six thousand, four hundred twelve".