215803861 has 32 divisors (see below), whose sum is σ = 272498688. Its totient is φ = 166380480.

The previous prime is 215803859. The next prime is 215803867. The reversal of 215803861 is 168308512.

It is not a de Polignac number, because 215803861 - 2¹ = 215803859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215803867) 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, 820416 + ... + 820678.

It is an arithmetic number, because the mean of its divisors is an integer number (8515584).

Almost surely, 2^215803861 is an apocalyptic number.

It is an amenable number.

215803861 is a deficient number, since it is larger than the sum of its proper divisors (56694827).

215803861 is a wasteful number, since it uses less digits than its factorization.

215803861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 215803861 is about 14690.2641569170. The cubic root of 215803861 is about 599.8183348166.

The spelling of 215803861 in words is "two hundred fifteen million, eight hundred three thousand, eight hundred sixty-one".