1021221111221 has 32 divisors (see below), whose sum is σ = 1091962023936. Its totient is φ = 953399808000.

The previous prime is 1021221111199. The next prime is 1021221111269. The reversal of 1021221111221 is 1221111221201.

It is a de Polignac number, because none of the positive numbers 2^k-1021221111221 is a prime.

It is a super-2 number, since 2×1021221111221² (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 1021221111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021221113221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 175434491 + ... + 175440311.

It is an arithmetic number, because the mean of its divisors is an integer number (34123813248).

Almost surely, 2^{1021221111221} is an apocalyptic number.

It is an amenable number.

1021221111221 is a deficient number, since it is larger than the sum of its proper divisors (70740912715).

1021221111221 is a wasteful number, since it uses less digits than its factorization.

1021221111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7413.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1021221111221 its reverse (1221111221201), we get a palindrome (2242332332422).

The spelling of 1021221111221 in words is "one trillion, twenty-one billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twenty-one".