21277261212 has 24 divisors (see below), whose sum is σ = 50009333136. Its totient is φ = 7040650368.

The previous prime is 21277261193. The next prime is 21277261219. The reversal of 21277261212 is 21216277212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21277261219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6469543 + ... + 6472830.

It is an arithmetic number, because the mean of its divisors is an integer number (2083722214).

Almost surely, 2^21277261212 is an apocalyptic number.

It is an amenable number.

21277261212 is an abundant number, since it is smaller than the sum of its proper divisors (28732071924).

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

21277261212 is a wasteful number, since it uses less digits than its factorization.

21277261212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12942517 (or 12942515 counting only the distinct ones).

The product of its digits is 9408, while the sum is 33.

The spelling of 21277261212 in words is "twenty-one billion, two hundred seventy-seven million, two hundred sixty-one thousand, two hundred twelve".