216403615 has 4 divisors (see below), whose sum is σ = 259684344. Its totient is φ = 173122888.

The previous prime is 216403613. The next prime is 216403633. The reversal of 216403615 is 516304612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216403615 - 2¹ = 216403613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216403613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21640357 + ... + 21640366.

It is an arithmetic number, because the mean of its divisors is an integer number (64921086).

Almost surely, 2^216403615 is an apocalyptic number.

216403615 is a deficient number, since it is larger than the sum of its proper divisors (43280729).

216403615 is an equidigital number, since it uses as much as digits as its factorization.

216403615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43280728.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 216403615 is about 14710.6633093141. The cubic root of 216403615 is about 600.3734850592.

The spelling of 216403615 in words is "two hundred sixteen million, four hundred three thousand, six hundred fifteen".