261964431 has 6 divisors (see below), whose sum is σ = 378393080. Its totient is φ = 174642948.

The previous prime is 261964429. The next prime is 261964447. The reversal of 261964431 is 134469162.

261964431 is a `hidden beast` number, since 2 + 6 + 1 + 9 + 644 + 3 + 1 = 666.

It is not a de Polignac number, because 261964431 - 2¹ = 261964429 is a prime.

It is a super-2 number, since 2×261964431² = 137250726218307522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261964231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14553571 + ... + 14553588.

Almost surely, 2^261964431 is an apocalyptic number.

261964431 is a deficient number, since it is larger than the sum of its proper divisors (116428649).

261964431 is a wasteful number, since it uses less digits than its factorization.

261964431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29107165 (or 29107162 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 261964431 is about 16185.3152888660. The cubic root of 261964431 is about 639.8538329937.

The spelling of 261964431 in words is "two hundred sixty-one million, nine hundred sixty-four thousand, four hundred thirty-one".