260639640 has 64 divisors (see below), whose sum is σ = 868802400. Its totient is φ = 69503616.

The previous prime is 260639633. The next prime is 260639683. The reversal of 260639640 is 46936062.

260639640 is a `hidden beast` number, since 2 + 6 + 0 + 6 + 3 + 9 + 640 = 666.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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 = 260639595 and 260639604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119587 + ... + 121746.

Almost surely, 2^260639640 is an apocalyptic number.

260639640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

260639640 is an abundant number, since it is smaller than the sum of its proper divisors (608162760).

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

260639640 is a wasteful number, since it uses less digits than its factorization.

260639640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241353 (or 241343 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 260639640 is about 16144.3377070724. The cubic root of 260639640 is about 638.7733993417.

The spelling of 260639640 in words is "two hundred sixty million, six hundred thirty-nine thousand, six hundred forty".