77445720 has 320 divisors, whose sum is σ = 296382240. Its totient is φ = 17971200.

The previous prime is 77445713. The next prime is 77445733. The reversal of 77445720 is 2754477.

It is a happy number.

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 polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1461214 + ... + 1461266.

Almost surely, 2^77445720 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 77445720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148191120).

77445720 is an abundant number, since it is smaller than the sum of its proper divisors (218936520).

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

77445720 is a wasteful number, since it uses less digits than its factorization.

77445720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 54880, while the sum is 36.

The square root of 77445720 is about 8800.3249939988. The cubic root of 77445720 is about 426.2513890157.

It can be divided in two parts, 774457 and 20, that added together give a palindrome (774477).

The spelling of 77445720 in words is "seventy-seven million, four hundred forty-five thousand, seven hundred twenty".