81974769 has 4 divisors (see below), whose sum is σ = 109299696. Its totient is φ = 54649844.

The previous prime is 81974741. The next prime is 81974771. The reversal of 81974769 is 96747918.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81974769 - 2¹¹ = 81972721 is a prime.

It is a super-2 number, since 2×81974769² = 13439725505206722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (82974769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13662459 + ... + 13662464.

It is an arithmetic number, because the mean of its divisors is an integer number (27324924).

Almost surely, 2^81974769 is an apocalyptic number.

It is an amenable number.

81974769 is a deficient number, since it is larger than the sum of its proper divisors (27324927).

81974769 is a wasteful number, since it uses less digits than its factorization.

81974769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27324926.

The product of its digits is 762048, while the sum is 51.

The square root of 81974769 is about 9053.9918820374. The cubic root of 81974769 is about 434.4035848138.

The spelling of 81974769 in words is "eighty-one million, nine hundred seventy-four thousand, seven hundred sixty-nine".