215581662893 has 2 divisors, whose sum is σ = 215581662894. Its totient is φ = 215581662892.

The previous prime is 215581662883. The next prime is 215581662931. The reversal of 215581662893 is 398266185512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130091505124 + 85490157769 = 360682^2 + 292387^2 .

It is a cyclic number.

It is not a de Polignac number, because 215581662893 - 2²⁴ = 215564885677 is a prime.

It is a super-2 number, since 2×215581662893² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215581662823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107790831446 + 107790831447.

It is an arithmetic number, because the mean of its divisors is an integer number (107790831447).

Almost surely, 2^215581662893 is an apocalyptic number.

It is an amenable number.

215581662893 is a deficient number, since it is larger than the sum of its proper divisors (1).

215581662893 is an equidigital number, since it uses as much as digits as its factorization.

215581662893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6220800, while the sum is 56.

The spelling of 215581662893 in words is "two hundred fifteen billion, five hundred eighty-one million, six hundred sixty-two thousand, eight hundred ninety-three".