77136420 has 24 divisors (see below), whose sum is σ = 215982144. Its totient is φ = 20569696.

The previous prime is 77136413. The next prime is 77136421. The reversal of 77136420 is 2463177.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (77136421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 642744 + ... + 642863.

It is an arithmetic number, because the mean of its divisors is an integer number (8999256).

Almost surely, 2^77136420 is an apocalyptic number.

It is an amenable number.

77136420 is an abundant number, since it is smaller than the sum of its proper divisors (138845724).

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

77136420 is a wasteful number, since it uses less digits than its factorization.

77136420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1285619 (or 1285617 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 77136420 is about 8782.7341984145. The cubic root of 77136420 is about 425.6831826335.

Adding to 77136420 its reverse (2463177), we get a palindrome (79599597).

The spelling of 77136420 in words is "seventy-seven million, one hundred thirty-six thousand, four hundred twenty".