1816865215 has 48 divisors (see below), whose sum is σ = 2539555200. Its totient is φ = 1243408320.

The previous prime is 1816865207. The next prime is 1816865227. The reversal of 1816865215 is 5125686181.

It is not a de Polignac number, because 1816865215 - 2³ = 1816865207 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2057164 + ... + 2058046.

It is an arithmetic number, because the mean of its divisors is an integer number (52907400).

Almost surely, 2^1816865215 is an apocalyptic number.

1816865215 is a deficient number, since it is larger than the sum of its proper divisors (722689985).

1816865215 is a wasteful number, since it uses less digits than its factorization.

1816865215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108 (or 1097 counting only the distinct ones).

The product of its digits is 115200, while the sum is 43.

The square root of 1816865215 is about 42624.7019344417. The cubic root of 1816865215 is about 1220.2277669792.

The spelling of 1816865215 in words is "one billion, eight hundred sixteen million, eight hundred sixty-five thousand, two hundred fifteen".