21234004121 has 4 divisors (see below), whose sum is σ = 23164368144. Its totient is φ = 19303640100.

The previous prime is 21234004109. The next prime is 21234004157. The reversal of 21234004121 is 12140043212.

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 not a de Polignac number, because 21234004121 - 2¹⁰ = 21234003097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21234004093 and 21234004102.

It is not an unprimeable number, because it can be changed into a prime (21234064121) 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, 965181995 + ... + 965182016.

It is an arithmetic number, because the mean of its divisors is an integer number (5791092036).

Almost surely, 2^21234004121 is an apocalyptic number.

It is an amenable number.

21234004121 is a deficient number, since it is larger than the sum of its proper divisors (1930364023).

21234004121 is a wasteful number, since it uses less digits than its factorization.

21234004121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1930364022.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21234004121 its reverse (12140043212), we get a palindrome (33374047333).

The spelling of 21234004121 in words is "twenty-one billion, two hundred thirty-four million, four thousand, one hundred twenty-one".