215121191 has 2 divisors, whose sum is σ = 215121192. Its totient is φ = 215121190.

The previous prime is 215121169. The next prime is 215121229. The reversal of 215121191 is 191121512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215121191 - 2¹⁰ = 215120167 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215121161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107560595 + 107560596.

It is an arithmetic number, because the mean of its divisors is an integer number (107560596).

Almost surely, 2^215121191 is an apocalyptic number.

215121191 is a deficient number, since it is larger than the sum of its proper divisors (1).

215121191 is an equidigital number, since it uses as much as digits as its factorization.

215121191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 23.

The square root of 215121191 is about 14667.0102952169. The cubic root of 215121191 is about 599.1851819164.

The spelling of 215121191 in words is "two hundred fifteen million, one hundred twenty-one thousand, one hundred ninety-one".