668921952 has 24 divisors (see below), whose sum is σ = 1755920376. Its totient is φ = 222973952.

The previous prime is 668921951. The next prime is 668921989. The reversal of 668921952 is 259129866.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668921951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3483873 + ... + 3484064.

It is an arithmetic number, because the mean of its divisors is an integer number (73163349).

Almost surely, 2^668921952 is an apocalyptic number.

It is an amenable number.

668921952 is an abundant number, since it is smaller than the sum of its proper divisors (1086998424).

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

668921952 is a wasteful number, since it uses less digits than its factorization.

668921952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6967950 (or 6967942 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The square root of 668921952 is about 25863.5255137423. The cubic root of 668921952 is about 874.5644425984.

The spelling of 668921952 in words is "six hundred sixty-eight million, nine hundred twenty-one thousand, nine hundred fifty-two".