77780128 has 24 divisors (see below), whose sum is σ = 153468000. Its totient is φ = 38804160.

The previous prime is 77780123. The next prime is 77780137. The reversal of 77780128 is 82108777.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (77780123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13533 + ... + 18403.

It is an arithmetic number, because the mean of its divisors is an integer number (6394500).

Almost surely, 2^77780128 is an apocalyptic number.

It is an amenable number.

77780128 is a deficient number, since it is larger than the sum of its proper divisors (75687872).

77780128 is a wasteful number, since it uses less digits than its factorization.

77780128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5380 (or 5372 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 40.

The square root of 77780128 is about 8819.3042809510. The cubic root of 77780128 is about 426.8640211129.

The spelling of 77780128 in words is "seventy-seven million, seven hundred eighty thousand, one hundred twenty-eight".