81633802 has 4 divisors (see below), whose sum is σ = 122450706. Its totient is φ = 40816900.

The previous prime is 81633793. The next prime is 81633817. The reversal of 81633802 is 20833618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 77951241 + 3682561 = 8829^2 + 1919^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20408449 + ... + 20408452.

Almost surely, 2^81633802 is an apocalyptic number.

81633802 is a deficient number, since it is larger than the sum of its proper divisors (40816904).

81633802 is a wasteful number, since it uses less digits than its factorization.

81633802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40816903.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 81633802 is about 9035.1426109387. The cubic root of 81633802 is about 433.8004597094.

The spelling of 81633802 in words is "eighty-one million, six hundred thirty-three thousand, eight hundred two".