81294813 has 16 divisors (see below), whose sum is σ = 120797760. Its totient is φ = 54034128.

The previous prime is 81294779. The next prime is 81294821. The reversal of 81294813 is 31849218.

It is not a de Polignac number, because 81294813 - 2⁸ = 81294557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81294823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5031 + ... + 13707.

It is an arithmetic number, because the mean of its divisors is an integer number (7549860).

Almost surely, 2^81294813 is an apocalyptic number.

It is an amenable number.

81294813 is a deficient number, since it is larger than the sum of its proper divisors (39502947).

81294813 is a wasteful number, since it uses less digits than its factorization.

81294813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9033 (or 9027 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 81294813 is about 9016.3636239894. The cubic root of 81294813 is about 433.1991662878.

The spelling of 81294813 in words is "eighty-one million, two hundred ninety-four thousand, eight hundred thirteen".