216501247 has 4 divisors (see below), whose sum is σ = 216629640. Its totient is φ = 216372856.

The previous prime is 216501217. The next prime is 216501251. The reversal of 216501247 is 742105612.

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 216501247 - 2⁷ = 216501119 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 (216501217) 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, 61633 + ... + 65050.

It is an arithmetic number, because the mean of its divisors is an integer number (54157410).

Almost surely, 2^216501247 is an apocalyptic number.

216501247 is a deficient number, since it is larger than the sum of its proper divisors (128393).

216501247 is a wasteful number, since it uses less digits than its factorization.

216501247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128392.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 216501247 is about 14713.9813442861. The cubic root of 216501247 is about 600.4637590462.

Adding to 216501247 its reverse (742105612), we get a palindrome (958606859).

The spelling of 216501247 in words is "two hundred sixteen million, five hundred one thousand, two hundred forty-seven".