81273964 has 12 divisors (see below), whose sum is σ = 142292584. Its totient is φ = 40618944.

The previous prime is 81273949. The next prime is 81273967. The reversal of 81273964 is 46937218.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81273967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15124 + ... + 19780.

It is a vampire number, since it can be written as 8726 ⋅ 9314 (with its own digits).

Almost surely, 2^81273964 is an apocalyptic number.

It is an amenable number.

81273964 is a deficient number, since it is larger than the sum of its proper divisors (61018620).

81273964 is a wasteful number, since it uses less digits than its factorization.

81273964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9024 (or 9022 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 81273964 is about 9015.2073742094. The cubic root of 81273964 is about 433.1621301338.

The spelling of 81273964 in words is "eighty-one million, two hundred seventy-three thousand, nine hundred sixty-four".