678640894 has 4 divisors (see below), whose sum is σ = 1017961344. Its totient is φ = 339320446.

The previous prime is 678640877. The next prime is 678640909. The reversal of 678640894 is 498046876.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169660222 + ... + 169660225.

It is an arithmetic number, because the mean of its divisors is an integer number (254490336).

Almost surely, 2^678640894 is an apocalyptic number.

678640894 is a deficient number, since it is larger than the sum of its proper divisors (339320450).

678640894 is a wasteful number, since it uses less digits than its factorization.

678640894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339320449.

The product of its (nonzero) digits is 2322432, while the sum is 52.

The square root of 678640894 is about 26050.7369185595. The cubic root of 678640894 is about 878.7796850949.

The spelling of 678640894 in words is "six hundred seventy-eight million, six hundred forty thousand, eight hundred ninety-four".