81944177 has 4 divisors (see below), whose sum is σ = 93650496. Its totient is φ = 70237860.

The previous prime is 81944173. The next prime is 81944209. The reversal of 81944177 is 77144918.

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, and also an emirpimes, since its reverse is a distinct semiprime: 77144918 = 2 ⋅38572459.

It is not a de Polignac number, because 81944177 - 2² = 81944173 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81944173) 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, 5853149 + ... + 5853162.

It is an arithmetic number, because the mean of its divisors is an integer number (23412624).

Almost surely, 2^81944177 is an apocalyptic number.

It is an amenable number.

81944177 is a deficient number, since it is larger than the sum of its proper divisors (11706319).

81944177 is a wasteful number, since it uses less digits than its factorization.

81944177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11706318.

The product of its digits is 56448, while the sum is 41.

The square root of 81944177 is about 9052.3023038341. The cubic root of 81944177 is about 434.3495400222.

The spelling of 81944177 in words is "eighty-one million, nine hundred forty-four thousand, one hundred seventy-seven".