668290789 has 2 divisors, whose sum is σ = 668290790. Its totient is φ = 668290788.

The previous prime is 668290787. The next prime is 668290793. The reversal of 668290789 is 987092866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 508141764 + 160149025 = 22542^2 + 12655^2 .

It is a cyclic number.

It is not a de Polignac number, because 668290789 - 2¹ = 668290787 is a prime.

It is a super-2 number, since 2×668290789² = 893225157324485042, which contains 22 as substring.

Together with 668290787, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668290787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334145394 + 334145395.

It is an arithmetic number, because the mean of its divisors is an integer number (334145395).

Almost surely, 2^668290789 is an apocalyptic number.

It is an amenable number.

668290789 is a deficient number, since it is larger than the sum of its proper divisors (1).

668290789 is an equidigital number, since it uses as much as digits as its factorization.

668290789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The square root of 668290789 is about 25851.3208366613. The cubic root of 668290789 is about 874.2892902093.

The spelling of 668290789 in words is "six hundred sixty-eight million, two hundred ninety thousand, seven hundred eighty-nine".