2157215143561 has 2 divisors, whose sum is σ = 2157215143562. Its totient is φ = 2157215143560.

The previous prime is 2157215143543. The next prime is 2157215143597. The reversal of 2157215143561 is 1653415127512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1743405985161 + 413809158400 = 1320381^2 + 643280^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157215143561 - 2⁵ = 2157215143529 is a prime.

It is not a weakly prime, because it can be changed into another prime (2157215141561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078607571780 + 1078607571781.

It is an arithmetic number, because the mean of its divisors is an integer number (1078607571781).

Almost surely, 2^{2157215143561} is an apocalyptic number.

It is an amenable number.

2157215143561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157215143561 is an equidigital number, since it uses as much as digits as its factorization.

2157215143561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 252000, while the sum is 43.

The spelling of 2157215143561 in words is "two trillion, one hundred fifty-seven billion, two hundred fifteen million, one hundred forty-three thousand, five hundred sixty-one".