12642887705021 has 6 divisors (see below), whose sum is σ = 14707032636510. Its totient is φ = 10836760889976.

The previous prime is 12642887705017. The next prime is 12642887705023. The reversal of 12642887705021 is 12050778824621.

It can be written as a sum of positive squares in only one way, i.e., 6773344579225 + 5869543125796 = 2602565^2 + 2422714^2 .

It is not a de Polignac number, because 12642887705021 - 2² = 12642887705017 is a prime.

It is a super-2 number, since 2×12642887705021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12642887705023) 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, 129009058166 + ... + 129009058263.

It is an arithmetic number, because the mean of its divisors is an integer number (2451172106085).

Almost surely, 2^{12642887705021} is an apocalyptic number.

It is an amenable number.

12642887705021 is a deficient number, since it is larger than the sum of its proper divisors (2064144931489).

12642887705021 is an equidigital number, since it uses as much as digits as its factorization.

12642887705021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258018116443 (or 258018116436 counting only the distinct ones).

The product of its (nonzero) digits is 3010560, while the sum is 53.

The spelling of 12642887705021 in words is "twelve trillion, six hundred forty-two billion, eight hundred eighty-seven million, seven hundred five thousand, twenty-one".