81970799 has 16 divisors (see below), whose sum is σ = 86169408. Its totient is φ = 77905152.

The previous prime is 81970793. The next prime is 81970813. The reversal of 81970799 is 99707918.

It is a cyclic number.

It is not a de Polignac number, because 81970799 - 2⁴ = 81970783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81970793) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 522029 + ... + 522185.

It is an arithmetic number, because the mean of its divisors is an integer number (5385588).

Almost surely, 2^81970799 is an apocalyptic number.

81970799 is a deficient number, since it is larger than the sum of its proper divisors (4198609).

81970799 is a wasteful number, since it uses less digits than its factorization.

81970799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434.

The product of its (nonzero) digits is 285768, while the sum is 50.

The square root of 81970799 is about 9053.7726390715. The cubic root of 81970799 is about 434.3965720460.

The spelling of 81970799 in words is "eighty-one million, nine hundred seventy thousand, seven hundred ninety-nine".