81973377 has 12 divisors (see below), whose sum is σ = 122791760. Its totient is φ = 54648756.

The previous prime is 81973349. The next prime is 81973387. The reversal of 81973377 is 77337918.

It is not a de Polignac number, because 81973377 - 2⁷ = 81973249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81973387) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 168427 + ... + 168912.

Almost surely, 2^81973377 is an apocalyptic number.

It is an amenable number.

81973377 is a deficient number, since it is larger than the sum of its proper divisors (40818383).

81973377 is an equidigital number, since it uses as much as digits as its factorization.

81973377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337354 (or 337342 counting only the distinct ones).

The product of its digits is 222264, while the sum is 45.

The square root of 81973377 is about 9053.9150095415. The cubic root of 81973377 is about 434.4011259548.

The spelling of 81973377 in words is "eighty-one million, nine hundred seventy-three thousand, three hundred seventy-seven".