81374168877 has 4 divisors (see below), whose sum is σ = 108498891840. Its totient is φ = 54249445916.

The previous prime is 81374168861. The next prime is 81374168891. The reversal of 81374168877 is 77886147318.

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 81374168877 - 2⁴ = 81374168861 is a prime.

It is a super-2 number, since 2×81374168877² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81374168877.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81374168807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13562361477 + ... + 13562361482.

It is an arithmetic number, because the mean of its divisors is an integer number (27124722960).

Almost surely, 2^81374168877 is an apocalyptic number.

It is an amenable number.

81374168877 is a deficient number, since it is larger than the sum of its proper divisors (27124722963).

81374168877 is a wasteful number, since it uses less digits than its factorization.

81374168877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27124722962.

The product of its digits is 12644352, while the sum is 60.

The spelling of 81374168877 in words is "eighty-one billion, three hundred seventy-four million, one hundred sixty-eight thousand, eight hundred seventy-seven".