668739473 has 2 divisors, whose sum is σ = 668739474. Its totient is φ = 668739472.

The previous prime is 668739469. The next prime is 668739481. The reversal of 668739473 is 374937866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 524547409 + 144192064 = 22903^2 + 12008^2 .

It is a cyclic number.

It is not a de Polignac number, because 668739473 - 2² = 668739469 is a prime.

It is not a weakly prime, because it can be changed into another prime (668739493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334369736 + 334369737.

It is an arithmetic number, because the mean of its divisors is an integer number (334369737).

Almost surely, 2^668739473 is an apocalyptic number.

It is an amenable number.

668739473 is a deficient number, since it is larger than the sum of its proper divisors (1).

668739473 is an equidigital number, since it uses as much as digits as its factorization.

668739473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4572288, while the sum is 53.

The square root of 668739473 is about 25859.9975444701. The cubic root of 668739473 is about 874.4849095735.

The spelling of 668739473 in words is "six hundred sixty-eight million, seven hundred thirty-nine thousand, four hundred seventy-three".