102111121221 has 24 divisors (see below), whose sum is σ = 140701395744. Its totient is φ = 65867826240.

The previous prime is 102111121159. The next prime is 102111121243. The reversal of 102111121221 is 122121111201.

It is a happy number.

It is not a de Polignac number, because 102111121221 - 2¹⁸ = 102110859077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 102111121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102111121271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 674686 + ... + 812048.

It is an arithmetic number, because the mean of its divisors is an integer number (5862558156).

Almost surely, 2^102111121221 is an apocalyptic number.

It is an amenable number.

102111121221 is a deficient number, since it is larger than the sum of its proper divisors (38590274523).

102111121221 is a wasteful number, since it uses less digits than its factorization.

102111121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137621 (or 137584 counting only the distinct ones).

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

Adding to 102111121221 its reverse (122121111201), we get a palindrome (224232232422).

The spelling of 102111121221 in words is "one hundred two billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".