77020077520 has 40 divisors (see below), whose sum is σ = 179094758184. Its totient is φ = 30804060672.

The previous prime is 77020077517. The next prime is 77020077521. The reversal of 77020077520 is 2577002077.

It can be written as a sum of positive squares in 4 ways, for example, as 27917063056 + 49103014464 = 167084^2 + 221592^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 77020077520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77020077521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 607482 + ... + 723238.

Almost surely, 2^77020077520 is an apocalyptic number.

It is an amenable number.

77020077520 is an abundant number, since it is smaller than the sum of its proper divisors (102074680664).

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

77020077520 is a wasteful number, since it uses less digits than its factorization.

77020077520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124087 (or 124081 counting only the distinct ones).

The product of its (nonzero) digits is 48020, while the sum is 37.

Adding to 77020077520 its reverse (2577002077), we get a palindrome (79597079597).

The spelling of 77020077520 in words is "seventy-seven billion, twenty million, seventy-seven thousand, five hundred twenty".