216506253 has 4 divisors (see below), whose sum is σ = 288675008. Its totient is φ = 144337500.

The previous prime is 216506249. The next prime is 216506287. The reversal of 216506253 is 352605612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 216506253 - 2² = 216506249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216506253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216506233) 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, 36084373 + ... + 36084378.

It is an arithmetic number, because the mean of its divisors is an integer number (72168752).

Almost surely, 2^216506253 is an apocalyptic number.

It is an amenable number.

216506253 is a deficient number, since it is larger than the sum of its proper divisors (72168755).

216506253 is an equidigital number, since it uses as much as digits as its factorization.

216506253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72168754.

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 216506253 is about 14714.1514536177. The cubic root of 216506253 is about 600.4683870386.

The spelling of 216506253 in words is "two hundred sixteen million, five hundred six thousand, two hundred fifty-three".