1211001442021 has 4 divisors (see below), whose sum is σ = 1384001648032. Its totient is φ = 1038001236012.

The previous prime is 1211001441931. The next prime is 1211001442033. The reversal of 1211001442021 is 1202441001121.

It is a happy number.

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 1211001442021 - 2²¹ = 1210999344869 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211001442021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211001442051) 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, 86500102995 + ... + 86500103008.

It is an arithmetic number, because the mean of its divisors is an integer number (346000412008).

Almost surely, 2^{1211001442021} is an apocalyptic number.

It is an amenable number.

1211001442021 is a deficient number, since it is larger than the sum of its proper divisors (173000206011).

1211001442021 is an equidigital number, since it uses as much as digits as its factorization.

1211001442021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173000206010.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1211001442021 its reverse (1202441001121), we get a palindrome (2413442443142).

The spelling of 1211001442021 in words is "one trillion, two hundred eleven billion, one million, four hundred forty-two thousand, twenty-one".