404521643900981 has 2 divisors, whose sum is σ = 404521643900982. Its totient is φ = 404521643900980.

The previous prime is 404521643900939. The next prime is 404521643900989. The reversal of 404521643900981 is 189009346125404.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 324716615811025 + 79805028089956 = 18019895^2 + 8933366^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-404521643900981 is a prime.

It is a super-2 number, since 2×404521643900981² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404521643900989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202260821950490 + 202260821950491.

It is an arithmetic number, because the mean of its divisors is an integer number (202260821950491).

Almost surely, 2^{404521643900981} is an apocalyptic number.

It is an amenable number.

404521643900981 is a deficient number, since it is larger than the sum of its proper divisors (1).

404521643900981 is an equidigital number, since it uses as much as digits as its factorization.

404521643900981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7464960, while the sum is 56.

The spelling of 404521643900981 in words is "four hundred four trillion, five hundred twenty-one billion, six hundred forty-three million, nine hundred thousand, nine hundred eighty-one".