21440120240 has 240 divisors, whose sum is σ = 63009467136. Its totient is φ = 6590937600.

The previous prime is 21440120227. The next prime is 21440120249. The reversal of 21440120240 is 4202104412.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (21440120249) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 131534399 + ... + 131534561.

Almost surely, 2^21440120240 is an apocalyptic number.

21440120240 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 21440120240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31504733568).

21440120240 is an abundant number, since it is smaller than the sum of its proper divisors (41569346896).

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

21440120240 is a wasteful number, since it uses less digits than its factorization.

21440120240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21440120240 its reverse (4202104412), we get a palindrome (25642224652).

The spelling of 21440120240 in words is "twenty-one billion, four hundred forty million, one hundred twenty thousand, two hundred forty".