81256877 has 8 divisors (see below), whose sum is σ = 87708600. Its totient is φ = 74833920.

The previous prime is 81256867. The next prime is 81256883. The reversal of 81256877 is 77865218.

It can be written as a sum of positive squares in 4 ways, for example, as 7107556 + 74149321 = 2666^2 + 8611^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81256877 - 2¹² = 81252781 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 (81256817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1124 + ... + 12797.

It is an arithmetic number, because the mean of its divisors is an integer number (10963575).

Almost surely, 2^81256877 is an apocalyptic number.

It is an amenable number.

81256877 is a deficient number, since it is larger than the sum of its proper divisors (6451723).

81256877 is a wasteful number, since it uses less digits than its factorization.

81256877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14383.

The product of its digits is 188160, while the sum is 44.

The square root of 81256877 is about 9014.2596479134. The cubic root of 81256877 is about 433.1317720720.

It can be divided in two parts, 8125 and 6877, that multiplied together give a square (55875625 = 7475²).

The spelling of 81256877 in words is "eighty-one million, two hundred fifty-six thousand, eight hundred seventy-seven".