18501835158661 has 2 divisors, whose sum is σ = 18501835158662. Its totient is φ = 18501835158660.

The previous prime is 18501835158643. The next prime is 18501835158787. The reversal of 18501835158661 is 16685153810581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16571941848225 + 1929893310436 = 4070865^2 + 1389206^2 .

It is a cyclic number.

It is not a de Polignac number, because 18501835158661 - 2⁵ = 18501835158629 is a prime.

It is a super-2 number, since 2×18501835158661² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18501835158596 and 18501835158605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18561835158661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9250917579330 + 9250917579331.

It is an arithmetic number, because the mean of its divisors is an integer number (9250917579331).

Almost surely, 2^{18501835158661} is an apocalyptic number.

It is an amenable number.

18501835158661 is a deficient number, since it is larger than the sum of its proper divisors (1).

18501835158661 is an equidigital number, since it uses as much as digits as its factorization.

18501835158661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912000, while the sum is 58.

The spelling of 18501835158661 in words is "eighteen trillion, five hundred one billion, eight hundred thirty-five million, one hundred fifty-eight thousand, six hundred sixty-one".