216399587 has 4 divisors (see below), whose sum is σ = 216701280. Its totient is φ = 216097896.

The previous prime is 216399581. The next prime is 216399593. The reversal of 216399587 is 785993612.

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

It is an interprime number because it is at equal distance from previous prime (216399581) and next prime (216399593).

It is a cyclic number.

It is not a de Polignac number, because 216399587 - 2⁶ = 216399523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216399581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149768 + ... + 151205.

It is an arithmetic number, because the mean of its divisors is an integer number (54175320).

Almost surely, 2^216399587 is an apocalyptic number.

216399587 is a deficient number, since it is larger than the sum of its proper divisors (301693).

216399587 is an equidigital number, since it uses as much as digits as its factorization.

216399587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301692.

The product of its digits is 816480, while the sum is 50.

The square root of 216399587 is about 14710.5264011863. The cubic root of 216399587 is about 600.3697600453.

The spelling of 216399587 in words is "two hundred sixteen million, three hundred ninety-nine thousand, five hundred eighty-seven".