77990400 has 180 divisors, whose sum is σ = 279518382. Its totient is φ = 20766720.

The previous prime is 77990387. The next prime is 77990417. The reversal of 77990400 is 409977.

It can be written as a sum of positive squares in 3 ways, for example, as 75481344 + 2509056 = 8688^2 + 1584^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 114862 + ... + 115538.

Almost surely, 2^77990400 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 77990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139759191).

77990400 is an abundant number, since it is smaller than the sum of its proper divisors (201527982).

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

77990400 is a wasteful number, since it uses less digits than its factorization.

77990400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The square root of 77990400 is about 8831.2173566276. The cubic root of 77990400 is about 427.2483385945.

The spelling of 77990400 in words is "seventy-seven million, nine hundred ninety thousand, four hundred".