81431295 has 16 divisors (see below), whose sum is σ = 142134912. Its totient is φ = 39481760.

The previous prime is 81431291. The next prime is 81431299. The reversal of 81431295 is 59213418.

It is an interprime number because it is at equal distance from previous prime (81431291) and next prime (81431299).

It is not a de Polignac number, because 81431295 - 2² = 81431291 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81431291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 246597 + ... + 246926.

It is an arithmetic number, because the mean of its divisors is an integer number (8883432).

Almost surely, 2^81431295 is an apocalyptic number.

81431295 is a deficient number, since it is larger than the sum of its proper divisors (60703617).

81431295 is a wasteful number, since it uses less digits than its factorization.

81431295 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493542.

The product of its digits is 8640, while the sum is 33.

The square root of 81431295 is about 9023.9290223272. The cubic root of 81431295 is about 433.4414565828.

The spelling of 81431295 in words is "eighty-one million, four hundred thirty-one thousand, two hundred ninety-five".