668557952 has 16 divisors (see below), whose sum is σ = 1331893050. Its totient is φ = 334278912.

The previous prime is 668557949. The next prime is 668557991. The reversal of 668557952 is 259755866.

It can be written as a sum of positive squares in only one way, i.e., 482944576 + 185613376 = 21976^2 + 13624^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a junction number, because it is equal to n+sod(n) for n = 668557894 and 668557903.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2611427 + ... + 2611682.

Almost surely, 2^668557952 is an apocalyptic number.

It is an amenable number.

668557952 is a deficient number, since it is larger than the sum of its proper divisors (663335098).

668557952 is an equidigital number, since it uses as much as digits as its factorization.

668557952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5223123 (or 5223111 counting only the distinct ones).

The product of its digits is 4536000, while the sum is 53.

The square root of 668557952 is about 25856.4876191644. The cubic root of 668557952 is about 874.4057797348.

The spelling of 668557952 in words is "six hundred sixty-eight million, five hundred fifty-seven thousand, nine hundred fifty-two".