21431121104 has 40 divisors (see below), whose sum is σ = 43192105320. Its totient is φ = 10288857600.

The previous prime is 21431121083. The next prime is 21431121109. The reversal of 21431121104 is 40112113412.

It can be written as a sum of positive squares in 4 ways, for example, as 80066704 + 21351054400 = 8948^2 + 146120^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431121109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43607 + ... + 211574.

It is an arithmetic number, because the mean of its divisors is an integer number (1079802633).

Almost surely, 2^21431121104 is an apocalyptic number.

It is an amenable number.

21431121104 is an abundant number, since it is smaller than the sum of its proper divisors (21760984216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21431121104 is a wasteful number, since it uses less digits than its factorization.

21431121104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255399 (or 255393 counting only the distinct ones).

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

Adding to 21431121104 its reverse (40112113412), we get a palindrome (61543234516).

The spelling of 21431121104 in words is "twenty-one billion, four hundred thirty-one million, one hundred twenty-one thousand, one hundred four".