21243041440 has 48 divisors (see below), whose sum is σ = 50935766112. Its totient is φ = 8370388224.

The previous prime is 21243041423. The next prime is 21243041453. The reversal of 21243041440 is 4414034212.

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, 980094 + ... + 1001533.

It is an arithmetic number, because the mean of its divisors is an integer number (1061161794).

Almost surely, 2^21243041440 is an apocalyptic number.

21243041440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243041440 is an abundant number, since it is smaller than the sum of its proper divisors (29692724672).

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

21243041440 is a wasteful number, since it uses less digits than its factorization.

21243041440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981709 (or 1981701 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21243041440 its reverse (4414034212), we get a palindrome (25657075652).

The spelling of 21243041440 in words is "twenty-one billion, two hundred forty-three million, forty-one thousand, four hundred forty".