81374817 has 4 divisors (see below), whose sum is σ = 108499760. Its totient is φ = 54249876.

The previous prime is 81374809. The next prime is 81374831. The reversal of 81374817 is 71847318.

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 not a de Polignac number, because 81374817 - 2³ = 81374809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81374807) 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, 13562467 + ... + 13562472.

It is an arithmetic number, because the mean of its divisors is an integer number (27124940).

Almost surely, 2^81374817 is an apocalyptic number.

It is an amenable number.

81374817 is a deficient number, since it is larger than the sum of its proper divisors (27124943).

81374817 is a wasteful number, since it uses less digits than its factorization.

81374817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27124942.

The product of its digits is 37632, while the sum is 39.

The square root of 81374817 is about 9020.7991331145. The cubic root of 81374817 is about 433.3412266149.

The spelling of 81374817 in words is "eighty-one million, three hundred seventy-four thousand, eight hundred seventeen".