391274062561 has 2 divisors, whose sum is σ = 391274062562. Its totient is φ = 391274062560.

The previous prime is 391274062541. The next prime is 391274062567. The reversal of 391274062561 is 165260472193.

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., 291998656161 + 99275406400 = 540369^2 + 315080^2 .

It is an emirp because it is prime and its reverse (165260472193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 391274062561 - 2³⁷ = 253835109089 is a prime.

It is not a weakly prime, because it can be changed into another prime (391274062567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195637031280 + 195637031281.

It is an arithmetic number, because the mean of its divisors is an integer number (195637031281).

Almost surely, 2^391274062561 is an apocalyptic number.

It is an amenable number.

391274062561 is a deficient number, since it is larger than the sum of its proper divisors (1).

391274062561 is an equidigital number, since it uses as much as digits as its factorization.

391274062561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 544320, while the sum is 46.

The spelling of 391274062561 in words is "three hundred ninety-one billion, two hundred seventy-four million, sixty-two thousand, five hundred sixty-one".