261620080 has 20 divisors (see below), whose sum is σ = 608266872. Its totient is φ = 104648000.

The previous prime is 261619951. The next prime is 261620119. The reversal of 261620080 is 80026162.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1635046 + ... + 1635205.

Almost surely, 2^261620080 is an apocalyptic number.

261620080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261620080 is an abundant number, since it is smaller than the sum of its proper divisors (346646792).

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

261620080 is a wasteful number, since it uses less digits than its factorization.

261620080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3270264 (or 3270258 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 261620080 is about 16174.6740307185. The cubic root of 261620080 is about 639.5733484514.

The spelling of 261620080 in words is "two hundred sixty-one million, six hundred twenty thousand, eighty".