77115720 has 192 divisors, whose sum is σ = 261999360. Its totient is φ = 18135040.

The previous prime is 77115719. The next prime is 77115739. The reversal of 77115720 is 2751177.

It is a super-2 number, since 2×77115720² = 11893668542236800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 682384 + ... + 682496.

It is an arithmetic number, because the mean of its divisors is an integer number (1364580).

Almost surely, 2^77115720 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 77115720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130999680).

77115720 is an abundant number, since it is smaller than the sum of its proper divisors (184883640).

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

77115720 is a wasteful number, since it uses less digits than its factorization.

77115720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 3430, while the sum is 30.

The square root of 77115720 is about 8781.5556708365. Note that the first 3 decimals coincide. The cubic root of 77115720 is about 425.6451010536.

Adding to 77115720 its reverse (2751177), we get a palindrome (79866897).

It can be divided in two parts, 771157 and 20, that added together give a palindrome (771177).

The spelling of 77115720 in words is "seventy-seven million, one hundred fifteen thousand, seven hundred twenty".