18251436770561 has 2 divisors, whose sum is σ = 18251436770562. Its totient is φ = 18251436770560.

The previous prime is 18251436770527. The next prime is 18251436770701. The reversal of 18251436770561 is 16507763415281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16314886210561 + 1936550560000 = 4039169^2 + 1391600^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18251436770561 is a prime.

It is a super-2 number, since 2×18251436770561² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18251436770497 and 18251436770506.

It is not a weakly prime, because it can be changed into another prime (18251436770761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9125718385280 + 9125718385281.

It is an arithmetic number, because the mean of its divisors is an integer number (9125718385281).

Almost surely, 2^{18251436770561} is an apocalyptic number.

It is an amenable number.

18251436770561 is a deficient number, since it is larger than the sum of its proper divisors (1).

18251436770561 is an equidigital number, since it uses as much as digits as its factorization.

18251436770561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8467200, while the sum is 56.

The spelling of 18251436770561 in words is "eighteen trillion, two hundred fifty-one billion, four hundred thirty-six million, seven hundred seventy thousand, five hundred sixty-one".