261422931 has 16 divisors (see below), whose sum is σ = 434573568. Its totient is φ = 135804000.

The previous prime is 261422927. The next prime is 261422933. The reversal of 261422931 is 139224162.

It is not a de Polignac number, because 261422931 - 2² = 261422927 is a prime.

It is a super-2 number, since 2×261422931² = 136683897705261522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261422933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 565620 + ... + 566081.

It is an arithmetic number, because the mean of its divisors is an integer number (27160848).

Almost surely, 2^261422931 is an apocalyptic number.

261422931 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

261422931 is a deficient number, since it is larger than the sum of its proper divisors (173150637).

261422931 is a wasteful number, since it uses less digits than its factorization.

261422931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1131722.

The product of its digits is 5184, while the sum is 30.

The square root of 261422931 is about 16168.5785089475. The cubic root of 261422931 is about 639.4126536859.

The spelling of 261422931 in words is "two hundred sixty-one million, four hundred twenty-two thousand, nine hundred thirty-one".