216531757213 has 8 divisors (see below), whose sum is σ = 229426735608. Its totient is φ = 203654313984.

The previous prime is 216531757163. The next prime is 216531757217. The reversal of 216531757213 is 312757135612.

It can be written as a sum of positive squares in 4 ways, for example, as 82413203929 + 134118553284 = 287077^2 + 366222^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216531757213 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 216531757213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216531757217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4358356 + ... + 4407757.

It is an arithmetic number, because the mean of its divisors is an integer number (28678341951).

Almost surely, 2^216531757213 is an apocalyptic number.

It is an amenable number.

216531757213 is a deficient number, since it is larger than the sum of its proper divisors (12894978395).

216531757213 is a wasteful number, since it uses less digits than its factorization.

216531757213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8767583.

The product of its digits is 264600, while the sum is 43.

The spelling of 216531757213 in words is "two hundred sixteen billion, five hundred thirty-one million, seven hundred fifty-seven thousand, two hundred thirteen".