1668902321 has 2 divisors, whose sum is σ = 1668902322. Its totient is φ = 1668902320.

The previous prime is 1668902299. The next prime is 1668902371. The reversal of 1668902321 is 1232098661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1297800625 + 371101696 = 36025^2 + 19264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668902321 is a prime.

It is not a weakly prime, because it can be changed into another prime (1668902371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834451160 + 834451161.

It is an arithmetic number, because the mean of its divisors is an integer number (834451161).

Almost surely, 2^1668902321 is an apocalyptic number.

It is an amenable number.

1668902321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668902321 is an equidigital number, since it uses as much as digits as its factorization.

1668902321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 1668902321 is about 40852.2009321407. The cubic root of 1668902321 is about 1186.1609968966.

The spelling of 1668902321 in words is "one billion, six hundred sixty-eight million, nine hundred two thousand, three hundred twenty-one".