21124413440 has 192 divisors, whose sum is σ = 55229428800. Its totient is φ = 7707820032.

The previous prime is 21124413439. The next prime is 21124413461. The reversal of 21124413440 is 4431442112.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11846789 + ... + 11848571.

It is an arithmetic number, because the mean of its divisors is an integer number (287653275).

Almost surely, 2^21124413440 is an apocalyptic number.

21124413440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21124413440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27614714400).

21124413440 is an abundant number, since it is smaller than the sum of its proper divisors (34105015360).

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

21124413440 is a wasteful number, since it uses less digits than its factorization.

21124413440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912 (or 1892 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

Adding to 21124413440 its reverse (4431442112), we get a palindrome (25555855552).

The spelling of 21124413440 in words is "twenty-one billion, one hundred twenty-four million, four hundred thirteen thousand, four hundred forty".