77428655880 has 32 divisors (see below), whose sum is σ = 232285968000. Its totient is φ = 20647641536.

The previous prime is 77428655827. The next prime is 77428655881. The reversal of 77428655880 is 8855682477.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (77428655881) 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, 322619280 + ... + 322619519.

It is an arithmetic number, because the mean of its divisors is an integer number (7258936500).

Almost surely, 2^77428655880 is an apocalyptic number.

It is an amenable number.

77428655880 is an abundant number, since it is smaller than the sum of its proper divisors (154857312120).

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

77428655880 is a wasteful number, since it uses less digits than its factorization.

77428655880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645238813 (or 645238809 counting only the distinct ones).

The product of its (nonzero) digits is 30105600, while the sum is 60.

The spelling of 77428655880 in words is "seventy-seven billion, four hundred twenty-eight million, six hundred fifty-five thousand, eight hundred eighty".