21431133340 has 24 divisors (see below), whose sum is σ = 46221743232. Its totient is φ = 8340765120.

The previous prime is 21431133323. The next prime is 21431133341. The reversal of 21431133340 is 4333113412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431133341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14479756 + ... + 14481235.

It is an arithmetic number, because the mean of its divisors is an integer number (1925905968).

Almost surely, 2^21431133340 is an apocalyptic number.

21431133340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21431133340 is an abundant number, since it is smaller than the sum of its proper divisors (24790609892).

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

21431133340 is a wasteful number, since it uses less digits than its factorization.

21431133340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28961037 (or 28961035 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

Adding to 21431133340 its reverse (4333113412), we get a palindrome (25764246752).

The spelling of 21431133340 in words is "twenty-one billion, four hundred thirty-one million, one hundred thirty-three thousand, three hundred forty".