21342431240 has 64 divisors (see below), whose sum is σ = 51883191360. Its totient is φ = 7854554880.

The previous prime is 21342431237. The next prime is 21342431251. The reversal of 21342431240 is 4213424312.

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

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, 92795 + ... + 226485.

It is an arithmetic number, because the mean of its divisors is an integer number (810674865).

Almost surely, 2^21342431240 is an apocalyptic number.

21342431240 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 21342431240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25941595680).

21342431240 is an abundant number, since it is smaller than the sum of its proper divisors (30540760120).

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

21342431240 is a wasteful number, since it uses less digits than its factorization.

21342431240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134022 (or 134018 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21342431240 its reverse (4213424312), we get a palindrome (25555855552).

The spelling of 21342431240 in words is "twenty-one billion, three hundred forty-two million, four hundred thirty-one thousand, two hundred forty".