21431225140 has 24 divisors (see below), whose sum is σ = 48467540520. Its totient is φ = 7913067648.

The previous prime is 21431225119. The next prime is 21431225143. The reversal of 21431225140 is 4152213412.

It can be written as a sum of positive squares in 4 ways, for example, as 3185699364 + 18245525776 = 56442^2 + 135076^2 .

It is a super-2 number, since 2×21431225140² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431225143) 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, 41213635 + ... + 41214154.

It is an arithmetic number, because the mean of its divisors is an integer number (2019480855).

Almost surely, 2^21431225140 is an apocalyptic number.

21431225140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21431225140 is an abundant number, since it is smaller than the sum of its proper divisors (27036315380).

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

21431225140 is a wasteful number, since it uses less digits than its factorization.

21431225140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82427811 (or 82427809 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21431225140 its reverse (4152213412), we get a palindrome (25583438552).

The spelling of 21431225140 in words is "twenty-one billion, four hundred thirty-one million, two hundred twenty-five thousand, one hundred forty".