21431332323440 has 40 divisors (see below), whose sum is σ = 53660759012448. Its totient is φ = 7913107319040.

The previous prime is 21431332323433. The next prime is 21431332323463. The reversal of 21431332323440 is 4432323313412.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 21431332323440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10303524116 + ... + 10303526195.

Almost surely, 2^{21431332323440} is an apocalyptic number.

21431332323440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21431332323440 is an abundant number, since it is smaller than the sum of its proper divisors (32229426689008).

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

21431332323440 is a wasteful number, since it uses less digits than its factorization.

21431332323440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20607050337 (or 20607050331 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 35.

Adding to 21431332323440 its reverse (4432323313412), we get a palindrome (25863655636852).

The spelling of 21431332323440 in words is "twenty-one trillion, four hundred thirty-one billion, three hundred thirty-two million, three hundred twenty-three thousand, four hundred forty".