215122987 has 2 divisors, whose sum is σ = 215122988. Its totient is φ = 215122986.

The previous prime is 215122961. The next prime is 215122991. The reversal of 215122987 is 789221512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215122987 is a prime.

It is not a weakly prime, because it can be changed into another prime (215122907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107561493 + 107561494.

It is an arithmetic number, because the mean of its divisors is an integer number (107561494).

Almost surely, 2^215122987 is an apocalyptic number.

215122987 is a deficient number, since it is larger than the sum of its proper divisors (1).

215122987 is an equidigital number, since it uses as much as digits as its factorization.

215122987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 215122987 is about 14667.0715209274. The cubic root of 215122987 is about 599.1868494006.

The spelling of 215122987 in words is "two hundred fifteen million, one hundred twenty-two thousand, nine hundred eighty-seven".