1211102020021 has 4 divisors (see below), whose sum is σ = 1211298537952. Its totient is φ = 1210905502092.

The previous prime is 1211102019943. The next prime is 1211102020031. The reversal of 1211102020021 is 1200202011121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1211102020021 - 2¹⁵ = 1211101987253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211102019983 and 1211102020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211102020031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98249721 + ... + 98262046.

It is an arithmetic number, because the mean of its divisors is an integer number (302824634488).

Almost surely, 2^{1211102020021} is an apocalyptic number.

It is an amenable number.

1211102020021 is a deficient number, since it is larger than the sum of its proper divisors (196517931).

1211102020021 is an equidigital number, since it uses as much as digits as its factorization.

1211102020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196517930.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1211102020021 its reverse (1200202011121), we get a palindrome (2411304031142).

The spelling of 1211102020021 in words is "one trillion, two hundred eleven billion, one hundred two million, twenty thousand, twenty-one".