2631257640 has 96 divisors (see below), whose sum is σ = 9329018400. Its totient is φ = 637879680.

The previous prime is 2631257639. The next prime is 2631257653. The reversal of 2631257640 is 467521362.

2631257640 is a `hidden beast` number, since 2 + 6 + 3 + 1 + 2 + 5 + 7 + 640 = 666.

2631257640 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2631257595 and 2631257604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 328270 + ... + 336189.

It is an arithmetic number, because the mean of its divisors is an integer number (97177275).

Almost surely, 2^2631257640 is an apocalyptic number.

2631257640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2631257640 is an abundant number, since it is smaller than the sum of its proper divisors (6697760760).

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

2631257640 is a wasteful number, since it uses less digits than its factorization.

2631257640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664487 (or 664480 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 2631257640 is about 51295.7857918172. The cubic root of 2631257640 is about 1380.5573677972.

The spelling of 2631257640 in words is "two billion, six hundred thirty-one million, two hundred fifty-seven thousand, six hundred forty".