81679737 has 4 divisors (see below), whose sum is σ = 108906320. Its totient is φ = 54453156.

The previous prime is 81679711. The next prime is 81679751. The reversal of 81679737 is 73797618.

It is a happy number.

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 81679737 - 2¹¹ = 81677689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81674737) 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, 13613287 + ... + 13613292.

It is an arithmetic number, because the mean of its divisors is an integer number (27226580).

Almost surely, 2^81679737 is an apocalyptic number.

It is an amenable number.

81679737 is a deficient number, since it is larger than the sum of its proper divisors (27226583).

81679737 is a wasteful number, since it uses less digits than its factorization.

81679737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27226582.

The product of its digits is 444528, while the sum is 48.

The square root of 81679737 is about 9037.6842719803. The cubic root of 81679737 is about 433.8818103561.

The spelling of 81679737 in words is "eighty-one million, six hundred seventy-nine thousand, seven hundred thirty-seven".