321816862541 has 2 divisors, whose sum is σ = 321816862542. Its totient is φ = 321816862540.

The previous prime is 321816862537. The next prime is 321816862567. The reversal of 321816862541 is 145268618123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 302229460516 + 19587402025 = 549754^2 + 139955^2 .

It is an emirp because it is prime and its reverse (145268618123) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 321816862541 - 2² = 321816862537 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321816862511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160908431270 + 160908431271.

It is an arithmetic number, because the mean of its divisors is an integer number (160908431271).

Almost surely, 2^321816862541 is an apocalyptic number.

It is an amenable number.

321816862541 is a deficient number, since it is larger than the sum of its proper divisors (1).

321816862541 is an equidigital number, since it uses as much as digits as its factorization.

321816862541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 552960, while the sum is 47.

The spelling of 321816862541 in words is "three hundred twenty-one billion, eight hundred sixteen million, eight hundred sixty-two thousand, five hundred forty-one".