678355391 has 16 divisors (see below), whose sum is σ = 789876480. Its totient is φ = 570525120.

The previous prime is 678355367. The next prime is 678355393. The reversal of 678355391 is 193553876.

It is a cyclic number.

It is not a de Polignac number, because 678355391 - 2²² = 674161087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678355393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 284195 + ... + 286571.

It is an arithmetic number, because the mean of its divisors is an integer number (49367280).

Almost surely, 2^678355391 is an apocalyptic number.

678355391 is a deficient number, since it is larger than the sum of its proper divisors (111521089).

678355391 is a wasteful number, since it uses less digits than its factorization.

678355391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3134.

The product of its digits is 680400, while the sum is 47.

The square root of 678355391 is about 26045.2565930920. The cubic root of 678355391 is about 878.6564341333.

The spelling of 678355391 in words is "six hundred seventy-eight million, three hundred fifty-five thousand, three hundred ninety-one".