216656247 has 4 divisors (see below), whose sum is σ = 288875000. Its totient is φ = 144437496.

The previous prime is 216656239. The next prime is 216656249. The reversal of 216656247 is 742656612.

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

It is not a de Polignac number, because 216656247 - 2³ = 216656239 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 (216656249) 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, 36109372 + ... + 36109377.

It is an arithmetic number, because the mean of its divisors is an integer number (72218750).

Almost surely, 2^216656247 is an apocalyptic number.

216656247 is a deficient number, since it is larger than the sum of its proper divisors (72218753).

216656247 is an equidigital number, since it uses as much as digits as its factorization.

216656247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72218752.

The product of its digits is 120960, while the sum is 39.

The square root of 216656247 is about 14719.2475011462. The cubic root of 216656247 is about 600.6070217783.

The spelling of 216656247 in words is "two hundred sixteen million, six hundred fifty-six thousand, two hundred forty-seven".