261490986 has 24 divisors (see below), whose sum is σ = 578620224. Its totient is φ = 85308840.

The previous prime is 261490973. The next prime is 261490997. The reversal of 261490986 is 689094162.

It is a happy 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 11 ways as a sum of consecutive naturals, for example, 153700 + ... + 155391.

It is an arithmetic number, because the mean of its divisors is an integer number (24109176).

Almost surely, 2^261490986 is an apocalyptic number.

261490986 is an abundant number, since it is smaller than the sum of its proper divisors (317129238).

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

261490986 is a wasteful number, since it uses less digits than its factorization.

261490986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309146 (or 309143 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 261490986 is about 16170.6829169333. The cubic root of 261490986 is about 639.4681339665.

The spelling of 261490986 in words is "two hundred sixty-one million, four hundred ninety thousand, nine hundred eighty-six".