261880156 has 12 divisors (see below), whose sum is σ = 460666192. Its totient is φ = 130261248.

The previous prime is 261880133. The next prime is 261880159. The reversal of 261880156 is 651088162.

It is a super-2 number, since 2×261880156² = 137162432213168672, which contains 22 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261880159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168840 + ... + 170383.

Almost surely, 2^261880156 is an apocalyptic number.

It is an amenable number.

261880156 is a deficient number, since it is larger than the sum of its proper divisors (198786036).

261880156 is a wasteful number, since it uses less digits than its factorization.

261880156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339420 (or 339418 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 261880156 is about 16182.7116392773. The cubic root of 261880156 is about 639.7852111264.

The spelling of 261880156 in words is "two hundred sixty-one million, eight hundred eighty thousand, one hundred fifty-six".