215387231 has 2 divisors, whose sum is σ = 215387232. Its totient is φ = 215387230.

The previous prime is 215387219. The next prime is 215387257. The reversal of 215387231 is 132783512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215387231 - 2²⁶ = 148278367 is a prime.

It is a super-2 number, since 2×215387231² = 92783318555694722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215387261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107693615 + 107693616.

It is an arithmetic number, because the mean of its divisors is an integer number (107693616).

Almost surely, 2^215387231 is an apocalyptic number.

215387231 is a deficient number, since it is larger than the sum of its proper divisors (1).

215387231 is an equidigital number, since it uses as much as digits as its factorization.

215387231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 32.

The square root of 215387231 is about 14676.0768259096. The cubic root of 215387231 is about 599.4320839181.

The spelling of 215387231 in words is "two hundred fifteen million, three hundred eighty-seven thousand, two hundred thirty-one".