216501011 has 4 divisors (see below), whose sum is σ = 216632400. Its totient is φ = 216369624.

The previous prime is 216500989. The next prime is 216501059. The reversal of 216501011 is 110105612.

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 216501011 - 2²² = 212306707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216501611) 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, 63191 + ... + 66528.

It is an arithmetic number, because the mean of its divisors is an integer number (54158100).

Almost surely, 2^216501011 is an apocalyptic number.

216501011 is a deficient number, since it is larger than the sum of its proper divisors (131389).

216501011 is a wasteful number, since it uses less digits than its factorization.

216501011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131388.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 216501011 is about 14713.9733247006. The cubic root of 216501011 is about 600.4635408650.

Adding to 216501011 its reverse (110105612), we get a palindrome (326606623).

The spelling of 216501011 in words is "two hundred sixteen million, five hundred one thousand, eleven".