21042341440 has 56 divisors (see below), whose sum is σ = 51329231352. Its totient is φ = 8211640320.

The previous prime is 21042341429. The next prime is 21042341473. The reversal of 21042341440 is 4414324012.

It can be written as a sum of positive squares in 4 ways, for example, as 1098304 + 21041243136 = 1048^2 + 145056^2 .

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, 788799 + ... + 815038.

It is an arithmetic number, because the mean of its divisors is an integer number (916593417).

Almost surely, 2^21042341440 is an apocalyptic number.

21042341440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21042341440 is an abundant number, since it is smaller than the sum of its proper divisors (30286889912).

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

21042341440 is a wasteful number, since it uses less digits than its factorization.

21042341440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1603895 (or 1603885 counting only the distinct ones).

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

Adding to 21042341440 its reverse (4414324012), we get a palindrome (25456665452).

The spelling of 21042341440 in words is "twenty-one billion, forty-two million, three hundred forty-one thousand, four hundred forty".