20021347 has 4 divisors (see below), whose sum is σ = 20040696. Its totient is φ = 20002000.

The previous prime is 20021341. The next prime is 20021357. The reversal of 20021347 is 74312002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021347 - 2¹¹ = 20019299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8029 + ... + 10222.

It is an arithmetic number, because the mean of its divisors is an integer number (5010174).

Almost surely, 2^20021347 is an apocalyptic number.

20021347 is a deficient number, since it is larger than the sum of its proper divisors (19349).

20021347 is a wasteful number, since it uses less digits than its factorization.

20021347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19348.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 20021347 is about 4474.5219856427. The cubic root of 20021347 is about 271.5383017750.

Adding to 20021347 its reverse (74312002), we get a palindrome (94333349).

The spelling of 20021347 in words is "twenty million, twenty-one thousand, three hundred forty-seven".