211220111310 has 128 divisors (see below), whose sum is σ = 579456581760. Its totient is φ = 48813981696.

The previous prime is 211220111303. The next prime is 211220111317. The reversal of 211220111310 is 13111022112.

It is an interprime number because it is at equal distance from previous prime (211220111303) and next prime (211220111317).

It is a super-2 number, since 2×211220111310² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 211220111310.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211220111317) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2672724 + ... + 2750616.

It is an arithmetic number, because the mean of its divisors is an integer number (4527004545).

Almost surely, 2^211220111310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211220111310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289728290880).

211220111310 is an abundant number, since it is smaller than the sum of its proper divisors (368236470450).

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

211220111310 is a wasteful number, since it uses less digits than its factorization.

211220111310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78342.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 211220111310 its reverse (13111022112), we get a palindrome (224331133422).

The spelling of 211220111310 in words is "two hundred eleven billion, two hundred twenty million, one hundred eleven thousand, three hundred ten".