21210240342 has 48 divisors (see below), whose sum is σ = 44763198480. Its totient is φ = 6697401984.

The previous prime is 21210240299. The next prime is 21210240391. The reversal of 21210240342 is 24304201212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 227784 + ... + 307092.

It is an arithmetic number, because the mean of its divisors is an integer number (932566635).

Almost surely, 2^21210240342 is an apocalyptic number.

21210240342 is an abundant number, since it is smaller than the sum of its proper divisors (23552958138).

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

21210240342 is a wasteful number, since it uses less digits than its factorization.

21210240342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79425 (or 79396 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21210240342 its reverse (24304201212), we get a palindrome (45514441554).

The spelling of 21210240342 in words is "twenty-one billion, two hundred ten million, two hundred forty thousand, three hundred forty-two".