81472312 has 8 divisors (see below), whose sum is σ = 152760600. Its totient is φ = 40736152.

The previous prime is 81472301. The next prime is 81472319. The reversal of 81472312 is 21327418.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81472319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5092012 + ... + 5092027.

It is an arithmetic number, because the mean of its divisors is an integer number (19095075).

Almost surely, 2^81472312 is an apocalyptic number.

It is an amenable number.

81472312 is a deficient number, since it is larger than the sum of its proper divisors (71288288).

81472312 is a wasteful number, since it uses less digits than its factorization.

81472312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10184045 (or 10184041 counting only the distinct ones).

The product of its digits is 2688, while the sum is 28.

The square root of 81472312 is about 9026.2014158781. The cubic root of 81472312 is about 433.5142192885.

The spelling of 81472312 in words is "eighty-one million, four hundred seventy-two thousand, three hundred twelve".