16461611015981 has 2 divisors, whose sum is σ = 16461611015982. Its totient is φ = 16461611015980.

The previous prime is 16461611015929. The next prime is 16461611016013. The reversal of 16461611015981 is 18951011616461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15324954384100 + 1136656631881 = 3914710^2 + 1066141^2 .

It is an emirp because it is prime and its reverse (18951011616461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16461611015981 - 2¹⁸ = 16461610753837 is a prime.

It is a super-2 number, since 2×16461611015981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16461611065981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8230805507990 + 8230805507991.

It is an arithmetic number, because the mean of its divisors is an integer number (8230805507991).

Almost surely, 2^{16461611015981} is an apocalyptic number.

It is an amenable number.

16461611015981 is a deficient number, since it is larger than the sum of its proper divisors (1).

16461611015981 is an equidigital number, since it uses as much as digits as its factorization.

16461611015981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 311040, while the sum is 50.

The spelling of 16461611015981 in words is "sixteen trillion, four hundred sixty-one billion, six hundred eleven million, fifteen thousand, nine hundred eighty-one".