668798172 has 72 divisors (see below), whose sum is σ = 1936561536. Its totient is φ = 190642464.

The previous prime is 668798171. The next prime is 668798183. The reversal of 668798172 is 271897866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668798171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 114843 + ... + 120525.

It is an arithmetic number, because the mean of its divisors is an integer number (26896688).

Almost surely, 2^668798172 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 668798172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (968280768).

668798172 is an abundant number, since it is smaller than the sum of its proper divisors (1267763364).

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

668798172 is a wasteful number, since it uses less digits than its factorization.

668798172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6167 (or 6162 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The square root of 668798172 is about 25861.1324578024. The cubic root of 668798172 is about 874.5104949671.

The spelling of 668798172 in words is "six hundred sixty-eight million, seven hundred ninety-eight thousand, one hundred seventy-two".