2643639957 has 64 divisors (see below), whose sum is σ = 4603484160. Its totient is φ = 1467994752.

The previous prime is 2643639949. The next prime is 2643639983. The reversal of 2643639957 is 7599363462.

It is not a de Polignac number, because 2643639957 - 2³ = 2643639949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2643639907) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1844113 + ... + 1845545.

It is an arithmetic number, because the mean of its divisors is an integer number (71929440).

Almost surely, 2^2643639957 is an apocalyptic number.

2643639957 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

2643639957 is a deficient number, since it is larger than the sum of its proper divisors (1959844203).

2643639957 is a wasteful number, since it uses less digits than its factorization.

2643639957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1719 (or 1713 counting only the distinct ones).

The product of its digits is 7348320, while the sum is 54.

The square root of 2643639957 is about 51416.3393971216. The cubic root of 2643639957 is about 1382.7195473123.

The spelling of 2643639957 in words is "two billion, six hundred forty-three million, six hundred thirty-nine thousand, nine hundred fifty-seven".