81974507 has 8 divisors (see below), whose sum is σ = 86371584. Its totient is φ = 77646888.

The previous prime is 81974491. The next prime is 81974521. The reversal of 81974507 is 70547918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81974507 - 2⁴ = 81974491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81974537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14933 + ... + 19670.

It is an arithmetic number, because the mean of its divisors is an integer number (10796448).

Almost surely, 2^81974507 is an apocalyptic number.

81974507 is a deficient number, since it is larger than the sum of its proper divisors (4397077).

81974507 is a wasteful number, since it uses less digits than its factorization.

81974507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34729.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 81974507 is about 9053.9774132698. The cubic root of 81974507 is about 434.4031220135.

The spelling of 81974507 in words is "eighty-one million, nine hundred seventy-four thousand, five hundred seven".