21102132121 has 4 divisors (see below), whose sum is σ = 24116722432. Its totient is φ = 18087541812.

The previous prime is 21102132091. The next prime is 21102132131. The reversal of 21102132121 is 12123120112.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102132121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102132095 and 21102132104.

It is not an unprimeable number, because it can be changed into a prime (21102132131) 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, 1507295145 + ... + 1507295158.

It is an arithmetic number, because the mean of its divisors is an integer number (6029180608).

Almost surely, 2^21102132121 is an apocalyptic number.

It is an amenable number.

21102132121 is a deficient number, since it is larger than the sum of its proper divisors (3014590311).

21102132121 is an equidigital number, since it uses as much as digits as its factorization.

21102132121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3014590310.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21102132121 its reverse (12123120112), we get a palindrome (33225252233).

The spelling of 21102132121 in words is "twenty-one billion, one hundred two million, one hundred thirty-two thousand, one hundred twenty-one".