81292479 has 8 divisors (see below), whose sum is σ = 108586800. Its totient is φ = 54096576.

The previous prime is 81292439. The next prime is 81292483. The reversal of 81292479 is 97429218.

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

It is not a de Polignac number, because 81292479 - 2⁸ = 81292223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81292479.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81292439) 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, 22654 + ... + 25995.

It is an arithmetic number, because the mean of its divisors is an integer number (13573350).

Almost surely, 2^81292479 is an apocalyptic number.

81292479 is a deficient number, since it is larger than the sum of its proper divisors (27294321).

81292479 is a wasteful number, since it uses less digits than its factorization.

81292479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49209.

The product of its digits is 72576, while the sum is 42.

The square root of 81292479 is about 9016.2341917233. The cubic root of 81292479 is about 433.1950204861.

The spelling of 81292479 in words is "eighty-one million, two hundred ninety-two thousand, four hundred seventy-nine".