77120400 has 120 divisors (see below), whose sum is σ = 282364864. Its totient is φ = 17625600.

The previous prime is 77120399. The next prime is 77120419. The reversal of 77120400 is 402177.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3810 + ... + 12990.

Almost surely, 2^77120400 is an apocalyptic number.

77120400 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141182432).

77120400 is an abundant number, since it is smaller than the sum of its proper divisors (205244464).

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

77120400 is a wasteful number, since it uses less digits than its factorization.

77120400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9209 (or 9198 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 77120400 is about 8781.8221343865. The cubic root of 77120400 is about 425.6537113983.

Adding to 77120400 its reverse (402177), we get a palindrome (77522577).

The spelling of 77120400 in words is "seventy-seven million, one hundred twenty thousand, four hundred".