81172408 has 16 divisors (see below), whose sum is σ = 160209000. Its totient is φ = 38450016.

The previous prime is 81172397. The next prime is 81172439. The reversal of 81172408 is 80427118.

It is a self number, because there is not a number n which added to its sum of digits gives 81172408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266863 + ... + 267166.

Almost surely, 2^81172408 is an apocalyptic number.

It is an amenable number.

81172408 is a deficient number, since it is larger than the sum of its proper divisors (79036592).

81172408 is a wasteful number, since it uses less digits than its factorization.

81172408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534054 (or 534050 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 81172408 is about 9009.5731308425. The cubic root of 81172408 is about 432.9816354771.

The spelling of 81172408 in words is "eighty-one million, one hundred seventy-two thousand, four hundred eight".