81973802 has 4 divisors (see below), whose sum is σ = 122960706. Its totient is φ = 40986900.

The previous prime is 81973799. The next prime is 81973811. The reversal of 81973802 is 20837918.

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., 81884401 + 89401 = 9049^2 + 299^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20493449 + ... + 20493452.

Almost surely, 2^81973802 is an apocalyptic number.

81973802 is a deficient number, since it is larger than the sum of its proper divisors (40986904).

81973802 is a wasteful number, since it uses less digits than its factorization.

81973802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40986903.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 81973802 is about 9053.9384800207. The cubic root of 81973802 is about 434.4018766870.

The spelling of 81973802 in words is "eighty-one million, nine hundred seventy-three thousand, eight hundred two".