81877183811 has 4 divisors (see below), whose sum is σ = 85437061392. Its totient is φ = 78317306232.

The previous prime is 81877183807. The next prime is 81877183813. The reversal of 81877183811 is 11838177818.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81877183811 - 2² = 81877183807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81877183813) 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, 1779938756 + ... + 1779938801.

It is an arithmetic number, because the mean of its divisors is an integer number (21359265348).

Almost surely, 2^81877183811 is an apocalyptic number.

81877183811 is a deficient number, since it is larger than the sum of its proper divisors (3559877581).

81877183811 is a wasteful number, since it uses less digits than its factorization.

81877183811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3559877580.

The product of its digits is 602112, while the sum is 53.

The spelling of 81877183811 in words is "eighty-one billion, eight hundred seventy-seven million, one hundred eighty-three thousand, eight hundred eleven".