81391294 has 8 divisors (see below), whose sum is σ = 123558120. Its totient is φ = 40205256.

The previous prime is 81391283. The next prime is 81391339. The reversal of 81391294 is 49219318.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244989 + ... + 245320.

It is an arithmetic number, because the mean of its divisors is an integer number (15444765).

Almost surely, 2^81391294 is an apocalyptic number.

81391294 is a deficient number, since it is larger than the sum of its proper divisors (42166826).

81391294 is a wasteful number, since it uses less digits than its factorization.

81391294 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490394.

The product of its digits is 15552, while the sum is 37.

The square root of 81391294 is about 9021.7123651777. The cubic root of 81391294 is about 433.3704726880.

The spelling of 81391294 in words is "eighty-one million, three hundred ninety-one thousand, two hundred ninety-four".