261497979 has 12 divisors (see below), whose sum is σ = 382501600. Its totient is φ = 172124784.

The previous prime is 261497963. The next prime is 261497993. The reversal of 261497979 is 979794162.

261497979 is a `hidden beast` number, since 2 + 61 + 497 + 97 + 9 = 666.

It is not a de Polignac number, because 261497979 - 2⁴ = 261497963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261497939) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 183184 + ... + 184605.

Almost surely, 2^261497979 is an apocalyptic number.

261497979 is a deficient number, since it is larger than the sum of its proper divisors (121003621).

261497979 is a wasteful number, since it uses less digits than its factorization.

261497979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367874 (or 367871 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 54.

The square root of 261497979 is about 16170.8991401220. The cubic root of 261497979 is about 639.4738343042.

The spelling of 261497979 in words is "two hundred sixty-one million, four hundred ninety-seven thousand, nine hundred seventy-nine".