211101001020 has 576 divisors, whose sum is σ = 826743730176. Its totient is φ = 42408437760.

The previous prime is 211101000959. The next prime is 211101001043. The reversal of 211101001020 is 20100101112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 211101000993 and 211101001011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 28481115 + ... + 28488525.

It is an arithmetic number, because the mean of its divisors is an integer number (1435318976).

Almost surely, 2^211101001020 is an apocalyptic number.

211101001020 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 211101001020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413371865088).

211101001020 is an abundant number, since it is smaller than the sum of its proper divisors (615642729156).

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

211101001020 is a wasteful number, since it uses less digits than its factorization.

211101001020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7530 (or 7525 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 211101001020 its reverse (20100101112), we get a palindrome (231201102132).

The spelling of 211101001020 in words is "two hundred eleven billion, one hundred one million, one thousand, twenty".