21244434140 has 24 divisors (see below), whose sum is σ = 45455074560. Its totient is φ = 8337437888.

The previous prime is 21244434061. The next prime is 21244434151. The reversal of 21244434140 is 4143444212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10019900 + ... + 10022019.

It is an arithmetic number, because the mean of its divisors is an integer number (1893961440).

Almost surely, 2^21244434140 is an apocalyptic number.

21244434140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21244434140 is an abundant number, since it is smaller than the sum of its proper divisors (24210640420).

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

21244434140 is a wasteful number, since it uses less digits than its factorization.

21244434140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20041981 (or 20041979 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 29.

Adding to 21244434140 its reverse (4143444212), we get a palindrome (25387878352).

The spelling of 21244434140 in words is "twenty-one billion, two hundred forty-four million, four hundred thirty-four thousand, one hundred forty".