81377 has 4 divisors (see below), whose sum is σ = 85680. Its totient is φ = 77076.

The previous prime is 81373. The next prime is 81401. The reversal of 81377 is 77318.

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 81377 - 2² = 81373 is a prime.

It is a super-2 number, since 2×81377² = 13244432258, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (81371) 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, 2123 + ... + 2160.

It is an arithmetic number, because the mean of its divisors is an integer number (21420).

2⁸¹³⁷⁷ is an apocalyptic number.

It is an amenable number.

81377 is a deficient number, since it is larger than the sum of its proper divisors (4303).

81377 is a wasteful number, since it uses less digits than its factorization.

81377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4302.

The product of its digits is 1176, while the sum is 26.

The square root of 81377 is about 285.2665420269. The cubic root of 81377 is about 43.3345101587.

The spelling of 81377 in words is "eighty-one thousand, three hundred seventy-seven".