261951431 has 8 divisors (see below), whose sum is σ = 299581824. Its totient is φ = 224373240.

The previous prime is 261951413. The next prime is 261951463. The reversal of 261951431 is 134159162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261951431 - 2⁶ = 261951367 is a prime.

It is a super-2 number, since 2×261951431² = 137237104405895522, 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 (261951401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1625 + ... + 22946.

It is an arithmetic number, because the mean of its divisors is an integer number (37447728).

Almost surely, 2^261951431 is an apocalyptic number.

261951431 is a deficient number, since it is larger than the sum of its proper divisors (37630393).

261951431 is a wasteful number, since it uses less digits than its factorization.

261951431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26101.

The product of its digits is 6480, while the sum is 32.

The square root of 261951431 is about 16184.9136852811. The cubic root of 261951431 is about 639.8432485575.

The spelling of 261951431 in words is "two hundred sixty-one million, nine hundred fifty-one thousand, four hundred thirty-one".