216512403 has 4 divisors (see below), whose sum is σ = 288683208. Its totient is φ = 144341600.

The previous prime is 216512369. The next prime is 216512447. The reversal of 216512403 is 304215612.

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 216512403 - 2⁸ = 216512147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216512203) 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, 36085398 + ... + 36085403.

It is an arithmetic number, because the mean of its divisors is an integer number (72170802).

Almost surely, 2^216512403 is an apocalyptic number.

216512403 is a deficient number, since it is larger than the sum of its proper divisors (72170805).

216512403 is an equidigital number, since it uses as much as digits as its factorization.

216512403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72170804.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 216512403 is about 14714.3604346230. The cubic root of 216512403 is about 600.4740725489.

The spelling of 216512403 in words is "two hundred sixteen million, five hundred twelve thousand, four hundred three".