1221010212021 has 16 divisors (see below), whose sum is σ = 1636163297280. Its totient is φ = 809937542960.

The previous prime is 1221010212017. The next prime is 1221010212031. The reversal of 1221010212021 is 1202120101221.

It is a cyclic number.

It is not a de Polignac number, because 1221010212021 - 2² = 1221010212017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221010212031) 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, 180676 + ... + 1573106.

It is an arithmetic number, because the mean of its divisors is an integer number (102260206080).

Almost surely, 2^{1221010212021} is an apocalyptic number.

It is an amenable number.

1221010212021 is a deficient number, since it is larger than the sum of its proper divisors (415153085259).

1221010212021 is a wasteful number, since it uses less digits than its factorization.

1221010212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1393896.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221010212021 its reverse (1202120101221), we get a palindrome (2423130313242).

The spelling of 1221010212021 in words is "one trillion, two hundred twenty-one billion, ten million, two hundred twelve thousand, twenty-one".