77970816 has 256 divisors, whose sum is σ = 287884800. Its totient is φ = 20183040.

The previous prime is 77970811. The next prime is 77970817. The reversal of 77970816 is 61807977.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77970811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 265966 + ... + 266258.

It is an arithmetic number, because the mean of its divisors is an integer number (1124550).

Almost surely, 2^77970816 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 77970816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143942400).

77970816 is an abundant number, since it is smaller than the sum of its proper divisors (209913984).

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

77970816 is a wasteful number, since it uses less digits than its factorization.

77970816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 77970816 is about 8830.1084931047. The cubic root of 77970816 is about 427.2125737998.

The spelling of 77970816 in words is "seventy-seven million, nine hundred seventy thousand, eight hundred sixteen".