215043940661761 has 2 divisors, whose sum is σ = 215043940661762. Its totient is φ = 215043940661760.

The previous prime is 215043940661651. The next prime is 215043940661773. The reversal of 215043940661761 is 167166049340512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184277394164161 + 30766546497600 = 13574881^2 + 5546760^2 .

It is a cyclic number.

It is not a de Polignac number, because 215043940661761 - 2⁴³ = 206247847639553 is a prime.

It is a super-2 number, since 2×215043940661761² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215043940061761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107521970330880 + 107521970330881.

It is an arithmetic number, because the mean of its divisors is an integer number (107521970330881).

Almost surely, 2^{215043940661761} is an apocalyptic number.

It is an amenable number.

215043940661761 is a deficient number, since it is larger than the sum of its proper divisors (1).

215043940661761 is an equidigital number, since it uses as much as digits as its factorization.

215043940661761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6531840, while the sum is 55.

The spelling of 215043940661761 in words is "two hundred fifteen trillion, forty-three billion, nine hundred forty million, six hundred sixty-one thousand, seven hundred sixty-one".