215525491 has 2 divisors, whose sum is σ = 215525492. Its totient is φ = 215525490.

The previous prime is 215525489. The next prime is 215525573. The reversal of 215525491 is 194525512.

215525491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215525491 - 2¹ = 215525489 is a prime.

Together with 215525489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (215525441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107762745 + 107762746.

It is an arithmetic number, because the mean of its divisors is an integer number (107762746).

Almost surely, 2^215525491 is an apocalyptic number.

215525491 is a deficient number, since it is larger than the sum of its proper divisors (1).

215525491 is an equidigital number, since it uses as much as digits as its factorization.

215525491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18000, while the sum is 34.

The square root of 215525491 is about 14680.7864571351. The cubic root of 215525491 is about 599.5603176926.

The spelling of 215525491 in words is "two hundred fifteen million, five hundred twenty-five thousand, four hundred ninety-one".