2638762640 has 20 divisors (see below), whose sum is σ = 6135123324. Its totient is φ = 1055505024.

The previous prime is 2638762613. The next prime is 2638762667. The reversal of 2638762640 is 462678362.

It is an interprime number because it is at equal distance from previous prime (2638762613) and next prime (2638762667).

It can be written as a sum of positive squares in 2 ways, for example, as 1297152256 + 1341610384 = 36016^2 + 36628^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 2638762591 and 2638762600.

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, 16492187 + ... + 16492346.

Almost surely, 2^2638762640 is an apocalyptic number.

2638762640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2638762640 is an abundant number, since it is smaller than the sum of its proper divisors (3496360684).

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

2638762640 is a wasteful number, since it uses less digits than its factorization.

2638762640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32984546 (or 32984540 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 44.

The square root of 2638762640 is about 51368.8878602603. The cubic root of 2638762640 is about 1381.8686859636.

The spelling of 2638762640 in words is "two billion, six hundred thirty-eight million, seven hundred sixty-two thousand, six hundred forty".