90177978771 has 48 divisors (see below), whose sum is σ = 141664723200. Its totient is φ = 55089429696.

The previous prime is 90177978769. The next prime is 90177978851. The reversal of 90177978771 is 17787977109.

It is not a de Polignac number, because 90177978771 - 2¹ = 90177978769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 90177978699 and 90177978708.

It is not an unprimeable number, because it can be changed into a prime (90177978701) 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 47 ways as a sum of consecutive naturals, for example, 697825 + ... + 816893.

It is an arithmetic number, because the mean of its divisors is an integer number (2951348400).

Almost surely, 2^90177978771 is an apocalyptic number.

90177978771 is a deficient number, since it is larger than the sum of its proper divisors (51486744429).

90177978771 is a wasteful number, since it uses less digits than its factorization.

90177978771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119240 (or 119237 counting only the distinct ones).

The product of its (nonzero) digits is 10890936, while the sum is 63.

The spelling of 90177978771 in words is "ninety billion, one hundred seventy-seven million, nine hundred seventy-eight thousand, seven hundred seventy-one".