216653439 has 4 divisors (see below), whose sum is σ = 288871256. Its totient is φ = 144435624.

The previous prime is 216653429. The next prime is 216653443. The reversal of 216653439 is 934356612.

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

It is not a de Polignac number, because 216653439 - 2⁹ = 216652927 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216653397 and 216653406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216653429) 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, 36108904 + ... + 36108909.

It is an arithmetic number, because the mean of its divisors is an integer number (72217814).

Almost surely, 2^216653439 is an apocalyptic number.

216653439 is a deficient number, since it is larger than the sum of its proper divisors (72217817).

216653439 is an equidigital number, since it uses as much as digits as its factorization.

216653439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72217816.

The product of its digits is 116640, while the sum is 39.

The square root of 216653439 is about 14719.1521155262. The cubic root of 216653439 is about 600.6044270199.

The spelling of 216653439 in words is "two hundred sixteen million, six hundred fifty-three thousand, four hundred thirty-nine".