1221120021111 has 8 divisors (see below), whose sum is σ = 1628167496304. Its totient is φ = 814076280000.

The previous prime is 1221120021083. The next prime is 1221120021133. The reversal of 1221120021111 is 1111200211221.

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 1221120021111 - 2¹³ = 1221120012919 is a prime.

It is a super-2 number, since 2×1221120021111² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221120021151) 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, 51390 + ... + 1563611.

It is an arithmetic number, because the mean of its divisors is an integer number (203520937038).

Almost surely, 2^{1221120021111} is an apocalyptic number.

1221120021111 is a deficient number, since it is larger than the sum of its proper divisors (407047475193).

1221120021111 is a wasteful number, since it uses less digits than its factorization.

1221120021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1867041.

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

Adding to 1221120021111 its reverse (1111200211221), we get a palindrome (2332320232332).

The spelling of 1221120021111 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, twenty-one thousand, one hundred eleven".