668821372 has 6 divisors (see below), whose sum is σ = 1170437408. Its totient is φ = 334410684.

The previous prime is 668821357. The next prime is 668821379. The reversal of 668821372 is 273128866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668821379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83602668 + ... + 83602675.

Almost surely, 2^668821372 is an apocalyptic number.

It is an amenable number.

668821372 is a deficient number, since it is larger than the sum of its proper divisors (501616036).

668821372 is a wasteful number, since it uses less digits than its factorization.

668821372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167205347 (or 167205345 counting only the distinct ones).

The product of its digits is 193536, while the sum is 43.

The square root of 668821372 is about 25861.5810034886. The cubic root of 668821372 is about 874.5206068412.

The spelling of 668821372 in words is "six hundred sixty-eight million, eight hundred twenty-one thousand, three hundred seventy-two".