634138778 has 16 divisors (see below), whose sum is σ = 1170718080. Its totient is φ = 250868016.

The previous prime is 634138763. The next prime is 634138789. The reversal of 634138778 is 877831436.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1741958 + ... + 1742321.

It is an arithmetic number, because the mean of its divisors is an integer number (73169880).

Almost surely, 2^634138778 is an apocalyptic number.

634138778 is a deficient number, since it is larger than the sum of its proper divisors (536579302).

634138778 is a wasteful number, since it uses less digits than its factorization.

634138778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3484301.

The product of its digits is 677376, while the sum is 47.

The square root of 634138778 is about 25182.1122624771. The cubic root of 634138778 is about 859.1350497786.

The spelling of 634138778 in words is "six hundred thirty-four million, one hundred thirty-eight thousand, seven hundred seventy-eight".