21431044140 has 48 divisors (see below), whose sum is σ = 65462100480. Its totient is φ = 5195404480.

The previous prime is 21431044127. The next prime is 21431044157. The reversal of 21431044140 is 4144013412.

It is a self number, because there is not a number n which added to its sum of digits gives 21431044140.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16234980 + ... + 16236299.

It is an arithmetic number, because the mean of its divisors is an integer number (1363793760).

Almost surely, 2^21431044140 is an apocalyptic number.

21431044140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21431044140 is an abundant number, since it is smaller than the sum of its proper divisors (44031056340).

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

21431044140 is a wasteful number, since it uses less digits than its factorization.

21431044140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32471302 (or 32471300 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21431044140 its reverse (4144013412), we get a palindrome (25575057552).

The spelling of 21431044140 in words is "twenty-one billion, four hundred thirty-one million, forty-four thousand, one hundred forty".