81877563 has 12 divisors (see below), whose sum is σ = 118441440. Its totient is φ = 54504816.

The previous prime is 81877561. The next prime is 81877567. The reversal of 81877563 is 36577818.

81877563 is a `hidden beast` number, since 8 + 1 + 87 + 7 + 563 = 666.

It is not a de Polignac number, because 81877563 - 2¹ = 81877561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81877561) 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, 145 + ... + 12797.

It is an arithmetic number, because the mean of its divisors is an integer number (9870120).

Almost surely, 2^81877563 is an apocalyptic number.

81877563 is a deficient number, since it is larger than the sum of its proper divisors (36563877).

81877563 is a wasteful number, since it uses less digits than its factorization.

81877563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13378 (or 13375 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 81877563 is about 9048.6221603071. The cubic root of 81877563 is about 434.2318110790.

The spelling of 81877563 in words is "eighty-one million, eight hundred seventy-seven thousand, five hundred sixty-three".