216331491869 has 4 divisors (see below), whose sum is σ = 216335300160. Its totient is φ = 216327683580.

The previous prime is 216331491811. The next prime is 216331491949. The reversal of 216331491869 is 968194133612.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216331491869 is a prime.

It is a super-2 number, since 2×216331491869² (a number of 23 digits) contains 22 as substring.

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 216331491869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216331493869) 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, 1817627 + ... + 1932984.

It is an arithmetic number, because the mean of its divisors is an integer number (54083825040).

Almost surely, 2^216331491869 is an apocalyptic number.

It is an amenable number.

216331491869 is a deficient number, since it is larger than the sum of its proper divisors (3808291).

216331491869 is an equidigital number, since it uses as much as digits as its factorization.

216331491869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3808290.

The product of its digits is 1679616, while the sum is 53.

The spelling of 216331491869 in words is "two hundred sixteen billion, three hundred thirty-one million, four hundred ninety-one thousand, eight hundred sixty-nine".