321613993 has 2 divisors, whose sum is σ = 321613994. Its totient is φ = 321613992.

The previous prime is 321613987. The next prime is 321614023. The reversal of 321613993 is 399316123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 285035689 + 36578304 = 16883^2 + 6048^2 .

It is a cyclic number.

It is not a de Polignac number, because 321613993 - 2²⁵ = 288059561 is a prime.

It is not a weakly prime, because it can be changed into another prime (321613793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160806996 + 160806997.

It is an arithmetic number, because the mean of its divisors is an integer number (160806997).

Almost surely, 2^321613993 is an apocalyptic number.

It is an amenable number.

321613993 is a deficient number, since it is larger than the sum of its proper divisors (1).

321613993 is an equidigital number, since it uses as much as digits as its factorization.

321613993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26244, while the sum is 37.

The square root of 321613993 is about 17933.5995550252. The cubic root of 321613993 is about 685.1384045551.

The spelling of 321613993 in words is "three hundred twenty-one million, six hundred thirteen thousand, nine hundred ninety-three".