81873356 has 54 divisors (see below), whose sum is σ = 158899860. Its totient is φ = 36894960.

The previous prime is 81873349. The next prime is 81873367. The reversal of 81873356 is 65337818.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1387655 + ... + 1387713.

It is an arithmetic number, because the mean of its divisors is an integer number (2942590).

Almost surely, 2^81873356 is an apocalyptic number.

It is an amenable number.

81873356 is a deficient number, since it is larger than the sum of its proper divisors (77026504).

81873356 is a wasteful number, since it uses less digits than its factorization.

81873356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 111 counting only the distinct ones).

The product of its digits is 120960, while the sum is 41.

The square root of 81873356 is about 9048.3896909892. The cubic root of 81873356 is about 434.2243737769.

The spelling of 81873356 in words is "eighty-one million, eight hundred seventy-three thousand, three hundred fifty-six".