102123511221 has 4 divisors (see below), whose sum is σ = 136164681632. Its totient is φ = 68082340812.

The previous prime is 102123511187. The next prime is 102123511253. The reversal of 102123511221 is 122115321201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 102123511221 - 2¹⁸ = 102123249077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102123511271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17020585201 + ... + 17020585206.

It is an arithmetic number, because the mean of its divisors is an integer number (34041170408).

Almost surely, 2^102123511221 is an apocalyptic number.

It is an amenable number.

102123511221 is a deficient number, since it is larger than the sum of its proper divisors (34041170411).

102123511221 is an equidigital number, since it uses as much as digits as its factorization.

102123511221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34041170410.

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 102123511221 its reverse (122115321201), we get a palindrome (224238832422).

The spelling of 102123511221 in words is "one hundred two billion, one hundred twenty-three million, five hundred eleven thousand, two hundred twenty-one".