215697993 has 32 divisors (see below), whose sum is σ = 339849216. Its totient is φ = 119134848.

The previous prime is 215697973. The next prime is 215698009. The reversal of 215697993 is 399796512.

It is a happy number.

215697993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 215697993 - 2¹² = 215693897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215697953) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80605 + ... + 83237.

It is an arithmetic number, because the mean of its divisors is an integer number (10620288).

Almost surely, 2^215697993 is an apocalyptic number.

It is an amenable number.

215697993 is a deficient number, since it is larger than the sum of its proper divisors (124151223).

215697993 is a wasteful number, since it uses less digits than its factorization.

215697993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2773.

The product of its digits is 918540, while the sum is 51.

The square root of 215697993 is about 14686.6603760011. The cubic root of 215697993 is about 599.7202334603.

The spelling of 215697993 in words is "two hundred fifteen million, six hundred ninety-seven thousand, nine hundred ninety-three".