77090920 has 64 divisors (see below), whose sum is σ = 186293520. Its totient is φ = 28606464.

The previous prime is 77090911. The next prime is 77090921. The reversal of 77090920 is 2909077.

It can be written as a sum of positive squares in 8 ways, for example, as 29398084 + 47692836 = 5422^2 + 6906^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (77090921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48864 + ... + 50416.

Almost surely, 2^77090920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77090920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93146760).

77090920 is an abundant number, since it is smaller than the sum of its proper divisors (109202600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77090920 is a wasteful number, since it uses less digits than its factorization.

77090920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1654 (or 1650 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 34.

The square root of 77090920 is about 8780.1435067999. The cubic root of 77090920 is about 425.5994677712.

Adding to 77090920 its reverse (2909077), we get a palindrome (79999997).

The spelling of 77090920 in words is "seventy-seven million, ninety thousand, nine hundred twenty".