261466681 has 24 divisors (see below), whose sum is σ = 319221056. Its totient is φ = 209744640.

The previous prime is 261466669. The next prime is 261466759. The reversal of 261466681 is 186664162.

It is a happy number.

It is not a de Polignac number, because 261466681 - 2⁹ = 261466169 is a prime.

It is a super-2 number, since 2×261466681² = 136729650546311522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261466631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 620851 + ... + 621271.

Almost surely, 2^261466681 is an apocalyptic number.

It is an amenable number.

261466681 is a deficient number, since it is larger than the sum of its proper divisors (57754375).

261466681 is a wasteful number, since it uses less digits than its factorization.

261466681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769 (or 752 counting only the distinct ones).

The product of its digits is 82944, while the sum is 40.

The square root of 261466681 is about 16169.9313851358. The cubic root of 261466681 is about 639.4483209769.

The spelling of 261466681 in words is "two hundred sixty-one million, four hundred sixty-six thousand, six hundred eighty-one".