678436538 has 16 divisors (see below), whose sum is σ = 1096821096. Its totient is φ = 312871680.

The previous prime is 678436531. The next prime is 678436547. The reversal of 678436538 is 835634876.

It can be written as a sum of positive squares in 4 ways, for example, as 552391009 + 126045529 = 23503^2 + 11227^2 .

It is a super-2 number, since 2×678436538² = 920552272186850888, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (678436531) 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, 24470 + ... + 44222.

Almost surely, 2^678436538 is an apocalyptic number.

678436538 is a deficient number, since it is larger than the sum of its proper divisors (418384558).

678436538 is a wasteful number, since it uses less digits than its factorization.

678436538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21089.

The product of its digits is 2903040, while the sum is 50.

The square root of 678436538 is about 26046.8143541586. The cubic root of 678436538 is about 878.6914686161.

The spelling of 678436538 in words is "six hundred seventy-eight million, four hundred thirty-six thousand, five hundred thirty-eight".