678491964 has 84 divisors (see below), whose sum is σ = 1885083984. Its totient is φ = 212844672.

The previous prime is 678491951. The next prime is 678491971. The reversal of 678491964 is 469194876.

678491964 is a `hidden beast` number, since 67 + 8 + 491 + 96 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 678491964.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 42729 + ... + 56415.

It is an arithmetic number, because the mean of its divisors is an integer number (22441476).

Almost surely, 2^678491964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 678491964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (942541992).

678491964 is an abundant number, since it is smaller than the sum of its proper divisors (1206592020).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

678491964 is a wasteful number, since it uses less digits than its factorization.

678491964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13726 (or 13709 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 54.

The square root of 678491964 is about 26047.8783013128. The cubic root of 678491964 is about 878.7153966843.

The spelling of 678491964 in words is "six hundred seventy-eight million, four hundred ninety-one thousand, nine hundred sixty-four".