1221143042021 has 16 divisors (see below), whose sum is σ = 1422525931008. Its totient is φ = 1026652060800.

The previous prime is 1221143041933. The next prime is 1221143042099. The reversal of 1221143042021 is 1202403411221.

It is a cyclic number.

It is not a de Polignac number, because 1221143042021 - 2¹⁴ = 1221143025637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221143042321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6508925 + ... + 6693906.

It is an arithmetic number, because the mean of its divisors is an integer number (88907870688).

Almost surely, 2^{1221143042021} is an apocalyptic number.

It is an amenable number.

1221143042021 is a deficient number, since it is larger than the sum of its proper divisors (201382888987).

1221143042021 is a wasteful number, since it uses less digits than its factorization.

1221143042021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13203092.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 1221143042021 its reverse (1202403411221), we get a palindrome (2423546453242).

The spelling of 1221143042021 in words is "one trillion, two hundred twenty-one billion, one hundred forty-three million, forty-two thousand, twenty-one".