2161061555231 has 2 divisors, whose sum is σ = 2161061555232. Its totient is φ = 2161061555230.

The previous prime is 2161061555221. The next prime is 2161061555273. The reversal of 2161061555231 is 1325551601612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161061555231 is a prime.

It is a super-2 number, since 2×2161061555231² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161061555221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080530777615 + 1080530777616.

It is an arithmetic number, because the mean of its divisors is an integer number (1080530777616).

Almost surely, 2^{2161061555231} is an apocalyptic number.

2161061555231 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161061555231 is an equidigital number, since it uses as much as digits as its factorization.

2161061555231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54000, while the sum is 38.

The spelling of 2161061555231 in words is "two trillion, one hundred sixty-one billion, sixty-one million, five hundred fifty-five thousand, two hundred thirty-one".