1211101100020 has 144 divisors (see below), whose sum is σ = 3128474603520. Its totient is φ = 392038617600.

The previous prime is 1211101099997. The next prime is 1211101100029. The reversal of 1211101100020 is 200011011121.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211101100029) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 759421 + ... + 1731739.

It is an arithmetic number, because the mean of its divisors is an integer number (21725518080).

Almost surely, 2^{1211101100020} is an apocalyptic number.

1211101100020 is a gapful number since it is divisible by the number (10) 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 1211101100020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1564237301760).

1211101100020 is an abundant number, since it is smaller than the sum of its proper divisors (1917373503500).

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

1211101100020 is a wasteful number, since it uses less digits than its factorization.

1211101100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972414 (or 972405 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 1211101100020 its reverse (200011011121), we get a palindrome (1411112111141).

The spelling of 1211101100020 in words is "one trillion, two hundred eleven billion, one hundred one million, one hundred thousand, twenty".