12757615821 has 6 divisors (see below), whose sum is σ = 18427667310. Its totient is φ = 8505077208.

The previous prime is 12757615817. The next prime is 12757615891. The reversal of 12757615821 is 12851675721.

12757615821 is a `hidden beast` number, since 1 + 2 + 7 + 5 + 7 + 61 + 582 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12609044100 + 148571721 = 112290^2 + 12189^2 .

It is not a de Polignac number, because 12757615821 - 2² = 12757615817 is a prime.

It is a super-2 number, since 2×12757615821² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12757615891) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 708756426 + ... + 708756443.

It is an arithmetic number, because the mean of its divisors is an integer number (3071277885).

Almost surely, 2^12757615821 is an apocalyptic number.

It is an amenable number.

12757615821 is a deficient number, since it is larger than the sum of its proper divisors (5670051489).

12757615821 is a wasteful number, since it uses less digits than its factorization.

12757615821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1417512875 (or 1417512872 counting only the distinct ones).

The product of its digits is 235200, while the sum is 45.

The spelling of 12757615821 in words is "twelve billion, seven hundred fifty-seven million, six hundred fifteen thousand, eight hundred twenty-one".