213511111020 has 288 divisors, whose sum is σ = 664575335424. Its totient is φ = 55472947200.

The previous prime is 213511111003. The next prime is 213511111027. The reversal of 213511111020 is 20111115312.

213511111020 is a `hidden beast` number, since 21 + 3 + 511 + 1 + 110 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 213511110984 and 213511111002.

It is not an unprimeable number, because it can be changed into a prime (213511111027) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 604847164 + ... + 604847516.

It is an arithmetic number, because the mean of its divisors is an integer number (2307553248).

Almost surely, 2^213511111020 is an apocalyptic number.

213511111020 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 213511111020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332287667712).

213511111020 is an abundant number, since it is smaller than the sum of its proper divisors (451064224404).

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

213511111020 is a wasteful number, since it uses less digits than its factorization.

213511111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873 (or 868 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 18.

Adding to 213511111020 its reverse (20111115312), we get a palindrome (233622226332).

The spelling of 213511111020 in words is "two hundred thirteen billion, five hundred eleven million, one hundred eleven thousand, twenty".