678139690 has 16 divisors (see below), whose sum is σ = 1292454792. Its totient is φ = 255299584.

The previous prime is 678139667. The next prime is 678139691. The reversal of 678139690 is 96931876.

678139690 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 676988361 + 1151329 = 26019^2 + 1073^2 .

It is a super-2 number, since 2×678139690² = 919746878306592200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (678139691) 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, 1994359 + ... + 1994698.

Almost surely, 2^678139690 is an apocalyptic number.

678139690 is a deficient number, since it is larger than the sum of its proper divisors (614315102).

678139690 is a wasteful number, since it uses less digits than its factorization.

678139690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3989081.

The product of its (nonzero) digits is 489888, while the sum is 49.

The square root of 678139690 is about 26041.1153754980. The cubic root of 678139690 is about 878.5632935928.

The spelling of 678139690 in words is "six hundred seventy-eight million, one hundred thirty-nine thousand, six hundred ninety".