77988420 has 96 divisors (see below), whose sum is σ = 245763840. Its totient is φ = 20785248.

The previous prime is 77988413. The next prime is 77988431. The reversal of 77988420 is 2488977.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42849 + ... + 44631.

It is an arithmetic number, because the mean of its divisors is an integer number (2560040).

Almost surely, 2^77988420 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 77988420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122881920).

77988420 is an abundant number, since it is smaller than the sum of its proper divisors (167775420).

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

77988420 is a wasteful number, since it uses less digits than its factorization.

77988420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1813 (or 1793 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The square root of 77988420 is about 8831.1052535909. The cubic root of 77988420 is about 427.2447229406.

The spelling of 77988420 in words is "seventy-seven million, nine hundred eighty-eight thousand, four hundred twenty".