261197579 has 16 divisors (see below), whose sum is σ = 278971680. Its totient is φ = 244532736.

The previous prime is 261197549. The next prime is 261197611. The reversal of 261197579 is 975791162.

It is not a de Polignac number, because 261197579 - 2¹² = 261193483 is a prime.

It is a super-2 number, since 2×261197579² = 136448350550922482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261197509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 774899 + ... + 775235.

It is an arithmetic number, because the mean of its divisors is an integer number (17435730).

Almost surely, 2^261197579 is an apocalyptic number.

261197579 is a deficient number, since it is larger than the sum of its proper divisors (17774101).

261197579 is an equidigital number, since it uses as much as digits as its factorization.

261197579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507 (or 469 counting only the distinct ones).

The product of its digits is 238140, while the sum is 47.

The square root of 261197579 is about 16161.6081811186. The cubic root of 261197579 is about 639.2288718688.

The spelling of 261197579 in words is "two hundred sixty-one million, one hundred ninety-seven thousand, five hundred seventy-nine".