211220004440 has 64 divisors (see below), whose sum is σ = 482066069760. Its totient is φ = 83276000640.

The previous prime is 211220004433. The next prime is 211220004449. The reversal of 211220004440 is 44400022112.

It is a super-2 number, since 2×211220004440² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211220004449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14496599 + ... + 14511161.

It is an arithmetic number, because the mean of its divisors is an integer number (7532282340).

Almost surely, 2^211220004440 is an apocalyptic number.

211220004440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211220004440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241033034880).

211220004440 is an abundant number, since it is smaller than the sum of its proper divisors (270846065320).

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

211220004440 is a wasteful number, since it uses less digits than its factorization.

211220004440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19752 (or 19748 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 211220004440 its reverse (44400022112), we get a palindrome (255620026552).

The spelling of 211220004440 in words is "two hundred eleven billion, two hundred twenty million, four thousand, four hundred forty".