216715915 has 32 divisors (see below), whose sum is σ = 303500736. Its totient is φ = 147087360.

The previous prime is 216715907. The next prime is 216715921. The reversal of 216715915 is 519517612.

It is not a de Polignac number, because 216715915 - 2³ = 216715907 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45235 + ... + 49795.

It is an arithmetic number, because the mean of its divisors is an integer number (9484398).

Almost surely, 2^216715915 is an apocalyptic number.

216715915 is a deficient number, since it is larger than the sum of its proper divisors (86784821).

216715915 is a wasteful number, since it uses less digits than its factorization.

216715915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4639.

The product of its digits is 18900, while the sum is 37.

The square root of 216715915 is about 14721.2742315331. The cubic root of 216715915 is about 600.6621532456.

The spelling of 216715915 in words is "two hundred sixteen million, seven hundred fifteen thousand, nine hundred fifteen".