20421432342 has 128 divisors (see below), whose sum is σ = 49909063680. Its totient is φ = 6161495040.

The previous prime is 20421432331. The next prime is 20421432371. The reversal of 20421432342 is 24323412402.

20421432342 is a `hidden beast` number, since 2 + 0 + 421 + 4 + 3 + 234 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4750338 + ... + 4754634.

It is an arithmetic number, because the mean of its divisors is an integer number (389914560).

Almost surely, 2^20421432342 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421432342, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24954531840).

20421432342 is an abundant number, since it is smaller than the sum of its proper divisors (29487631338).

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

20421432342 is a wasteful number, since it uses less digits than its factorization.

20421432342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4523 (or 4517 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 20421432342 its reverse (24323412402), we get a palindrome (44744844744).

The spelling of 20421432342 in words is "twenty billion, four hundred twenty-one million, four hundred thirty-two thousand, three hundred forty-two".