2181156532729 has 2 divisors, whose sum is σ = 2181156532730. Its totient is φ = 2181156532728.

The previous prime is 2181156532601. The next prime is 2181156532739. The reversal of 2181156532729 is 9272356511812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1181836417129 + 999320115600 = 1087123^2 + 999660^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181156532729 - 2⁷ = 2181156532601 is a prime.

It is not a weakly prime, because it can be changed into another prime (2181156532739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090578266364 + 1090578266365.

It is an arithmetic number, because the mean of its divisors is an integer number (1090578266365).

Almost surely, 2^{2181156532729} is an apocalyptic number.

It is an amenable number.

2181156532729 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181156532729 is an equidigital number, since it uses as much as digits as its factorization.

2181156532729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1814400, while the sum is 52.

The spelling of 2181156532729 in words is "two trillion, one hundred eighty-one billion, one hundred fifty-six million, five hundred thirty-two thousand, seven hundred twenty-nine".