21230240240 has 40 divisors (see below), whose sum is σ = 53847611568. Its totient is φ = 7720087040.

The previous prime is 21230240177. The next prime is 21230240243. The reversal of 21230240240 is 4204203212.

It is a tau number, because it is divible by the number of its divisors (40).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230240243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12061757 + ... + 12063516.

Almost surely, 2^21230240240 is an apocalyptic number.

21230240240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21230240240 is an abundant number, since it is smaller than the sum of its proper divisors (32617371328).

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

21230240240 is a wasteful number, since it uses less digits than its factorization.

21230240240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24125297 (or 24125291 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21230240240 its reverse (4204203212), we get a palindrome (25434443452).

The spelling of 21230240240 in words is "twenty-one billion, two hundred thirty million, two hundred forty thousand, two hundred forty".