321516641 has 2 divisors, whose sum is σ = 321516642. Its totient is φ = 321516640.

The previous prime is 321516619. The next prime is 321516653. The reversal of 321516641 is 146615123.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 321449041 + 67600 = 17929^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 321516641 - 2¹⁰ = 321515617 is a prime.

It is not a weakly prime, because it can be changed into another prime (321516541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160758320 + 160758321.

It is an arithmetic number, because the mean of its divisors is an integer number (160758321).

Almost surely, 2^321516641 is an apocalyptic number.

It is an amenable number.

321516641 is a deficient number, since it is larger than the sum of its proper divisors (1).

321516641 is an equidigital number, since it uses as much as digits as its factorization.

321516641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 321516641 is about 17930.8851147956. The cubic root of 321516641 is about 685.0692675083.

The spelling of 321516641 in words is "three hundred twenty-one million, five hundred sixteen thousand, six hundred forty-one".