628779555 has 24 divisors (see below), whose sum is σ = 1091585040. Its totient is φ = 334825920.

The previous prime is 628779551. The next prime is 628779563. The reversal of 628779555 is 555977826.

628779555 is a `hidden beast` number, since 6 + 2 + 87 + 7 + 9 + 555 = 666.

628779555 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 628779555 - 2² = 628779551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (628779551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19176 + ... + 40314.

It is an arithmetic number, because the mean of its divisors is an integer number (45482710).

Almost surely, 2^628779555 is an apocalyptic number.

628779555 is a deficient number, since it is larger than the sum of its proper divisors (462805485).

628779555 is a wasteful number, since it uses less digits than its factorization.

628779555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21811 (or 21808 counting only the distinct ones).

The product of its digits is 5292000, while the sum is 54.

The square root of 628779555 is about 25075.4771639544. The cubic root of 628779555 is about 856.7079637282.

The spelling of 628779555 in words is "six hundred twenty-eight million, seven hundred seventy-nine thousand, five hundred fifty-five".