81913803 has 8 divisors (see below), whose sum is σ = 115643088. Its totient is φ = 51396864.

The previous prime is 81913781. The next prime is 81913817. The reversal of 81913803 is 30831918.

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

It is not a de Polignac number, because 81913803 - 2²⁵ = 48359371 is a prime.

It is a super-2 number, since 2×81913803² = 13419742243845618, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (81913003) 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, 803026 + ... + 803127.

It is an arithmetic number, because the mean of its divisors is an integer number (14455386).

Almost surely, 2^81913803 is an apocalyptic number.

81913803 is a deficient number, since it is larger than the sum of its proper divisors (33729285).

81913803 is a wasteful number, since it uses less digits than its factorization.

81913803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606173.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 81913803 is about 9050.6244535943. The cubic root of 81913803 is about 434.2958670470.

The spelling of 81913803 in words is "eighty-one million, nine hundred thirteen thousand, eight hundred three".