216145447 has 4 divisors (see below), whose sum is σ = 247023376. Its totient is φ = 185267520.

The previous prime is 216145427. The next prime is 216145469. The reversal of 216145447 is 744541612.

216145447 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 216145447 - 2¹⁵ = 216112679 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 (216145427) 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, 15438954 + ... + 15438967.

It is an arithmetic number, because the mean of its divisors is an integer number (61755844).

Almost surely, 2^216145447 is an apocalyptic number.

216145447 is a deficient number, since it is larger than the sum of its proper divisors (30877929).

216145447 is an equidigital number, since it uses as much as digits as its factorization.

216145447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30877928.

The product of its digits is 26880, while the sum is 34.

The square root of 216145447 is about 14701.8858314163. The cubic root of 216145447 is about 600.1346429314.

The spelling of 216145447 in words is "two hundred sixteen million, one hundred forty-five thousand, four hundred forty-seven".