261402680 has 64 divisors (see below), whose sum is σ = 733294080. Its totient is φ = 81475200.

The previous prime is 261402679. The next prime is 261402697. The reversal of 261402680 is 86204162.

It is a super-2 number, since 2×261402680² = 136662722222364800, which contains 22 as substring.

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, 39356 + ... + 45515.

It is an arithmetic number, because the mean of its divisors is an integer number (11457720).

Almost surely, 2^261402680 is an apocalyptic number.

261402680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261402680 is an abundant number, since it is smaller than the sum of its proper divisors (471891400).

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

261402680 is a wasteful number, since it uses less digits than its factorization.

261402680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84900 (or 84896 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 261402680 is about 16167.9522512902. The cubic root of 261402680 is about 639.3961426630.

The spelling of 261402680 in words is "two hundred sixty-one million, four hundred two thousand, six hundred eighty".