77940720 has 240 divisors, whose sum is σ = 307917792. Its totient is φ = 17418240.

The previous prime is 77940701. The next prime is 77940739. The reversal of 77940720 is 2704977.

It is an interprime number because it is at equal distance from previous prime (77940701) and next prime (77940739).

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 102582 + ... + 103338.

Almost surely, 2^77940720 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 77940720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153958896).

77940720 is an abundant number, since it is smaller than the sum of its proper divisors (229977072).

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

77940720 is a wasteful number, since it uses less digits than its factorization.

77940720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 36.

The square root of 77940720 is about 8828.4041593031. The cubic root of 77940720 is about 427.1576000506.

The spelling of 77940720 in words is "seventy-seven million, nine hundred forty thousand, seven hundred twenty".