21276953965 has 12 divisors (see below), whose sum is σ = 26690715324. Its totient is φ = 16281493184.

The previous prime is 21276953947. The next prime is 21276954043. The reversal of 21276953965 is 56935967212.

It can be written as a sum of positive squares in 2 ways, for example, as 7695149284 + 13581804681 = 87722^2 + 116541^2 .

It is not a de Polignac number, because 21276953965 - 2⁷ = 21276953837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4019464 + ... + 4024753.

It is an arithmetic number, because the mean of its divisors is an integer number (2224226277).

Almost surely, 2^21276953965 is an apocalyptic number.

It is an amenable number.

21276953965 is a deficient number, since it is larger than the sum of its proper divisors (5413761359).

21276953965 is an equidigital number, since it uses as much as digits as its factorization.

21276953965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8044268 (or 8044245 counting only the distinct ones).

The product of its digits is 6123600, while the sum is 55.

The spelling of 21276953965 in words is "twenty-one billion, two hundred seventy-six million, nine hundred fifty-three thousand, nine hundred sixty-five".