396550391561 has 2 divisors, whose sum is σ = 396550391562. Its totient is φ = 396550391560.

The previous prime is 396550391537. The next prime is 396550391621. The reversal of 396550391561 is 165193055693.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 396396160000 + 154231561 = 629600^2 + 12419^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-396550391561 is a prime.

It is not a weakly prime, because it can be changed into another prime (396550331561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198275195780 + 198275195781.

It is an arithmetic number, because the mean of its divisors is an integer number (198275195781).

Almost surely, 2^396550391561 is an apocalyptic number.

It is an amenable number.

396550391561 is a deficient number, since it is larger than the sum of its proper divisors (1).

396550391561 is an equidigital number, since it uses as much as digits as its factorization.

396550391561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3280500, while the sum is 53.

The spelling of 396550391561 in words is "three hundred ninety-six billion, five hundred fifty million, three hundred ninety-one thousand, five hundred sixty-one".