1211010121221 has 8 divisors (see below), whose sum is σ = 1615810104480. Its totient is φ = 806775109392.

The previous prime is 1211010121171. The next prime is 1211010121229. The reversal of 1211010121221 is 1221210101121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1211010121221 - 2²¹ = 1211008024069 is a prime.

It is a super-2 number, since 2×1211010121221² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1211010121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211010121229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141237855 + ... + 141246428.

It is an arithmetic number, because the mean of its divisors is an integer number (201976263060).

Almost surely, 2^{1211010121221} is an apocalyptic number.

It is an amenable number.

1211010121221 is a deficient number, since it is larger than the sum of its proper divisors (404799983259).

1211010121221 is a wasteful number, since it uses less digits than its factorization.

1211010121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282485715.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1211010121221 its reverse (1221210101121), we get a palindrome (2432220222342).

The spelling of 1211010121221 in words is "one trillion, two hundred eleven billion, ten million, one hundred twenty-one thousand, two hundred twenty-one".