321152561 has 2 divisors, whose sum is σ = 321152562. Its totient is φ = 321152560.

The previous prime is 321152537. The next prime is 321152567. The reversal of 321152561 is 165251123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 302064400 + 19088161 = 17380^2 + 4369^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321152561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 321152561.

It is not a weakly prime, because it can be changed into another prime (321152567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160576280 + 160576281.

It is an arithmetic number, because the mean of its divisors is an integer number (160576281).

Almost surely, 2^321152561 is an apocalyptic number.

It is an amenable number.

321152561 is a deficient number, since it is larger than the sum of its proper divisors (1).

321152561 is an equidigital number, since it uses as much as digits as its factorization.

321152561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1800, while the sum is 26.

The square root of 321152561 is about 17920.7299237503. The cubic root of 321152561 is about 684.8105828943.

The spelling of 321152561 in words is "three hundred twenty-one million, one hundred fifty-two thousand, five hundred sixty-one".