12642738820 has 12 divisors (see below), whose sum is σ = 26549751564. Its totient is φ = 5057095520.

The previous prime is 12642738817. The next prime is 12642738847. The reversal of 12642738820 is 2883724621.

It can be written as a sum of positive squares in 2 ways, for example, as 5036457024 + 7606281796 = 70968^2 + 87214^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 316068451 + ... + 316068490.

It is an arithmetic number, because the mean of its divisors is an integer number (2212479297).

Almost surely, 2^12642738820 is an apocalyptic number.

12642738820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12642738820 is an abundant number, since it is smaller than the sum of its proper divisors (13907012744).

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

12642738820 is a wasteful number, since it uses less digits than its factorization.

12642738820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632136950 (or 632136948 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 43.

The spelling of 12642738820 in words is "twelve billion, six hundred forty-two million, seven hundred thirty-eight thousand, eight hundred twenty".