684173979 has 32 divisors (see below), whose sum is σ = 1038873600. Its totient is φ = 444843360.

The previous prime is 684173969. The next prime is 684174013. The reversal of 684173979 is 979371486.

It is a happy number.

It is not a de Polignac number, because 684173979 - 2¹⁶ = 684108443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (684173909) 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, 254814 + ... + 257484.

It is an arithmetic number, because the mean of its divisors is an integer number (32464800).

Almost surely, 2^684173979 is an apocalyptic number.

684173979 is a deficient number, since it is larger than the sum of its proper divisors (354699621).

684173979 is a wasteful number, since it uses less digits than its factorization.

684173979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2912 (or 2906 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The square root of 684173979 is about 26156.7195764301. The cubic root of 684173979 is about 881.1615081808.

The spelling of 684173979 in words is "six hundred eighty-four million, one hundred seventy-three thousand, nine hundred seventy-nine".