21277619812 has 24 divisors (see below), whose sum is σ = 39047513400. Its totient is φ = 10131238656.

The previous prime is 21277619809. The next prime is 21277619863. The reversal of 21277619812 is 21891677212.

It can be written as a sum of positive squares in 4 ways, for example, as 11324365056 + 9953254756 = 106416^2 + 99766^2 .

It is an unprimeable number.

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, 1247887 + ... + 1264822.

It is an arithmetic number, because the mean of its divisors is an integer number (1626979725).

Almost surely, 2^21277619812 is an apocalyptic number.

It is an amenable number.

21277619812 is a deficient number, since it is larger than the sum of its proper divisors (17769893588).

21277619812 is a wasteful number, since it uses less digits than its factorization.

21277619812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2512815 (or 2512813 counting only the distinct ones).

The product of its digits is 169344, while the sum is 46.

The spelling of 21277619812 in words is "twenty-one billion, two hundred seventy-seven million, six hundred nineteen thousand, eight hundred twelve".