213186196561 has 16 divisors (see below), whose sum is σ = 233729220816. Its totient is φ = 193258331136.

The previous prime is 213186196523. The next prime is 213186196567. The reversal of 213186196561 is 165691681312.

It can be written as a sum of positive squares in 8 ways, for example, as 162409536 + 213023787025 = 12744^2 + 461545^2 .

It is not a de Polignac number, because 213186196561 - 2²¹ = 213184099409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (213186196567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 260950 + ... + 703183.

It is an arithmetic number, because the mean of its divisors is an integer number (14608076301).

Almost surely, 2^213186196561 is an apocalyptic number.

It is an amenable number.

213186196561 is a deficient number, since it is larger than the sum of its proper divisors (20543024255).

213186196561 is a wasteful number, since it uses less digits than its factorization.

213186196561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 964452.

The product of its digits is 466560, while the sum is 49.

The spelling of 213186196561 in words is "two hundred thirteen billion, one hundred eighty-six million, one hundred ninety-six thousand, five hundred sixty-one".