319927721 has 2 divisors, whose sum is σ = 319927722. Its totient is φ = 319927720.

The previous prime is 319927717. The next prime is 319927763. The reversal of 319927721 is 127729913.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 224670121 + 95257600 = 14989^2 + 9760^2 .

It is a cyclic number.

It is not a de Polignac number, because 319927721 - 2² = 319927717 is a prime.

It is not a weakly prime, because it can be changed into another prime (319927121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159963860 + 159963861.

It is an arithmetic number, because the mean of its divisors is an integer number (159963861).

Almost surely, 2^319927721 is an apocalyptic number.

It is an amenable number.

319927721 is a deficient number, since it is larger than the sum of its proper divisors (1).

319927721 is an equidigital number, since it uses as much as digits as its factorization.

319927721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47628, while the sum is 41.

The square root of 319927721 is about 17886.5234464387. The cubic root of 319927721 is about 683.9388767298.

The spelling of 319927721 in words is "three hundred nineteen million, nine hundred twenty-seven thousand, seven hundred twenty-one".