215091987 has 16 divisors (see below), whose sum is σ = 313182720. Its totient is φ = 130224800.

The previous prime is 215091959. The next prime is 215092049. The reversal of 215091987 is 789190512.

It is a cyclic number.

It is not a de Polignac number, because 215091987 - 2¹⁵ = 215059219 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215091287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36214 + ... + 41732.

It is an arithmetic number, because the mean of its divisors is an integer number (19573920).

Almost surely, 2^215091987 is an apocalyptic number.

215091987 is a deficient number, since it is larger than the sum of its proper divisors (98090733).

215091987 is a wasteful number, since it uses less digits than its factorization.

215091987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6714.

The product of its (nonzero) digits is 45360, while the sum is 42.

The square root of 215091987 is about 14666.0146938424. The cubic root of 215091987 is about 599.1580663544.

The spelling of 215091987 in words is "two hundred fifteen million, ninety-one thousand, nine hundred eighty-seven".