81877967 has 4 divisors (see below), whose sum is σ = 86694336. Its totient is φ = 77061600.

The previous prime is 81877963. The next prime is 81877969. The reversal of 81877967 is 76977818.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76977818 = 2 ⋅38488909.

It is a cyclic number.

It is not a de Polignac number, because 81877967 - 2² = 81877963 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81877963) 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, 2408159 + ... + 2408192.

It is an arithmetic number, because the mean of its divisors is an integer number (21673584).

Almost surely, 2^81877967 is an apocalyptic number.

81877967 is a deficient number, since it is larger than the sum of its proper divisors (4816369).

81877967 is a wasteful number, since it uses less digits than its factorization.

81877967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4816368.

The product of its digits is 1185408, while the sum is 53.

The square root of 81877967 is about 9048.6444841203. The cubic root of 81877967 is about 434.2325252729.

The spelling of 81877967 in words is "eighty-one million, eight hundred seventy-seven thousand, nine hundred sixty-seven".