20421340342 has 8 divisors (see below), whose sum is σ = 32988319056. Its totient is φ = 9425233992.

The previous prime is 20421340339. The next prime is 20421340363. The reversal of 20421340342 is 24304312402.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20421340342² (a number of 21 digits) contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 392718058 + ... + 392718109.

It is an arithmetic number, because the mean of its divisors is an integer number (4123539882).

Almost surely, 2^20421340342 is an apocalyptic number.

20421340342 is a deficient number, since it is larger than the sum of its proper divisors (12566978714).

20421340342 is a wasteful number, since it uses less digits than its factorization.

20421340342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785436182.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 20421340342 its reverse (24304312402), we get a palindrome (44725652744).

The spelling of 20421340342 in words is "twenty billion, four hundred twenty-one million, three hundred forty thousand, three hundred forty-two".