21331761512 has 8 divisors (see below), whose sum is σ = 39997052850. Its totient is φ = 10665880752.

The previous prime is 21331761487. The next prime is 21331761523. The reversal of 21331761512 is 21516713312.

It can be written as a sum of positive squares in only one way, i.e., 20670963076 + 660798436 = 143774^2 + 25706^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21331761512² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333235087 + ... + 1333235102.

Almost surely, 2^21331761512 is an apocalyptic number.

It is an amenable number.

21331761512 is a deficient number, since it is larger than the sum of its proper divisors (18665291338).

21331761512 is a wasteful number, since it uses less digits than its factorization.

21331761512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2666470195 (or 2666470191 counting only the distinct ones).

The product of its digits is 7560, while the sum is 32.

The spelling of 21331761512 in words is "twenty-one billion, three hundred thirty-one million, seven hundred sixty-one thousand, five hundred twelve".