218491191156 has 192 divisors, whose sum is σ = 615761879040. Its totient is φ = 59002352640.

The previous prime is 218491191133. The next prime is 218491191209. The reversal of 218491191156 is 651191194812.

It is a super-2 number, since 2×218491191156² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15101766 + ... + 15116226.

It is an arithmetic number, because the mean of its divisors is an integer number (3207093120).

Almost surely, 2^218491191156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218491191156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307880939520).

218491191156 is an abundant number, since it is smaller than the sum of its proper divisors (397270687884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218491191156 is a wasteful number, since it uses less digits than its factorization.

218491191156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14654 (or 14652 counting only the distinct ones).

The product of its digits is 155520, while the sum is 48.

The spelling of 218491191156 in words is "two hundred eighteen billion, four hundred ninety-one million, one hundred ninety-one thousand, one hundred fifty-six".