778520138 has 16 divisors (see below), whose sum is σ = 1317872160. Its totient is φ = 341670000.

The previous prime is 778520131. The next prime is 778520189. The reversal of 778520138 is 831025877.

778520138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 778520095 and 778520104.

It is not an unprimeable number, because it can be changed into a prime (778520131) 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, 609488 + ... + 610763.

It is an arithmetic number, because the mean of its divisors is an integer number (82367010).

Almost surely, 2^778520138 is an apocalyptic number.

778520138 is a deficient number, since it is larger than the sum of its proper divisors (539352022).

778520138 is a wasteful number, since it uses less digits than its factorization.

778520138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220293.

The product of its (nonzero) digits is 94080, while the sum is 41.

The square root of 778520138 is about 27901.9737294694. The cubic root of 778520138 is about 919.9338870260.

The spelling of 778520138 in words is "seven hundred seventy-eight million, five hundred twenty thousand, one hundred thirty-eight".