77128306 has 4 divisors (see below), whose sum is σ = 115692462. Its totient is φ = 38564152.

The previous prime is 77128301. The next prime is 77128309. The reversal of 77128306 is 60382177.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60382177 = 4801 ⋅12577.

It can be written as a sum of positive squares in only one way, i.e., 66830625 + 10297681 = 8175^2 + 3209^2 .

It is not an unprimeable number, because it can be changed into a prime (77128301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19282075 + ... + 19282078.

Almost surely, 2^77128306 is an apocalyptic number.

77128306 is a deficient number, since it is larger than the sum of its proper divisors (38564156).

77128306 is a wasteful number, since it uses less digits than its factorization.

77128306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38564155.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 77128306 is about 8782.2722572236. The cubic root of 77128306 is about 425.6682562020.

The spelling of 77128306 in words is "seventy-seven million, one hundred twenty-eight thousand, three hundred six".