81974755 has 4 divisors (see below), whose sum is σ = 98369712. Its totient is φ = 65579800.

The previous prime is 81974741. The next prime is 81974771. The reversal of 81974755 is 55747918.

It is a happy number.

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

It is not a de Polignac number, because 81974755 - 2⁵ = 81974723 is a prime.

It is a Duffinian 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, 8197471 + ... + 8197480.

It is an arithmetic number, because the mean of its divisors is an integer number (24592428).

Almost surely, 2^81974755 is an apocalyptic number.

81974755 is a deficient number, since it is larger than the sum of its proper divisors (16394957).

81974755 is a wasteful number, since it uses less digits than its factorization.

81974755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16394956.

The product of its digits is 352800, while the sum is 46.

The square root of 81974755 is about 9053.9911088978. The cubic root of 81974755 is about 434.4035600841.

The spelling of 81974755 in words is "eighty-one million, nine hundred seventy-four thousand, seven hundred fifty-five".