21014431121 has 4 divisors (see below), whose sum is σ = 21200399652. Its totient is φ = 20828462592.

The previous prime is 21014431117. The next prime is 21014431133. The reversal of 21014431121 is 12113441012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 403809025 + 20610622096 = 20095^2 + 143564^2 .

It is a cyclic number.

It is not a de Polignac number, because 21014431121 - 2² = 21014431117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21014431093 and 21014431102.

It is not an unprimeable number, because it can be changed into a prime (21014431181) 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, 92984096 + ... + 92984321.

It is an arithmetic number, because the mean of its divisors is an integer number (5300099913).

Almost surely, 2^21014431121 is an apocalyptic number.

It is an amenable number.

21014431121 is a deficient number, since it is larger than the sum of its proper divisors (185968531).

21014431121 is a wasteful number, since it uses less digits than its factorization.

21014431121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185968530.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21014431121 its reverse (12113441012), we get a palindrome (33127872133).

The spelling of 21014431121 in words is "twenty-one billion, fourteen million, four hundred thirty-one thousand, one hundred twenty-one".