679544640 has 224 divisors, whose sum is σ = 2429377920. Its totient is φ = 181025280.

The previous prime is 679544639. The next prime is 679544647. The reversal of 679544640 is 46445976.

679544640 is a `hidden beast` number, since 67 + 9 + 544 + 6 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (679544647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 699355 + ... + 700325.

Almost surely, 2^679544640 is an apocalyptic number.

679544640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 679544640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1214688960).

679544640 is an abundant number, since it is smaller than the sum of its proper divisors (1749833280).

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

679544640 is an frugal number, since it uses more digits than its factorization.

679544640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1009 (or 981 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 679544640 is about 26068.0770291942. The cubic root of 679544640 is about 879.1696023302.

The spelling of 679544640 in words is "six hundred seventy-nine million, five hundred forty-four thousand, six hundred forty".