1221021112110 has 64 divisors (see below), whose sum is σ = 3025711079424. Its totient is φ = 315026208000.

The previous prime is 1221021112081. The next prime is 1221021112147. The reversal of 1221021112110 is 112111201221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221021112110.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3750667 + ... + 4063193.

It is an arithmetic number, because the mean of its divisors is an integer number (47276735616).

Almost surely, 2^{1221021112110} is an apocalyptic number.

1221021112110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221021112110 is an abundant number, since it is smaller than the sum of its proper divisors (1804689967314).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221021112110 is a wasteful number, since it uses less digits than its factorization.

1221021112110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316769.

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

Adding to 1221021112110 its reverse (112111201221), we get a palindrome (1333132313331).

The spelling of 1221021112110 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred twelve thousand, one hundred ten".