20021395 has 4 divisors (see below), whose sum is σ = 24025680. Its totient is φ = 16017112.

The previous prime is 20021387. The next prime is 20021399. The reversal of 20021395 is 59312002.

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 20021395 - 2³ = 20021387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20021399) 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, 2002135 + ... + 2002144.

It is an arithmetic number, because the mean of its divisors is an integer number (6006420).

Almost surely, 2^20021395 is an apocalyptic number.

20021395 is a deficient number, since it is larger than the sum of its proper divisors (4004285).

20021395 is an equidigital number, since it uses as much as digits as its factorization.

20021395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4004284.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 20021395 is about 4474.5273493409. The cubic root of 20021395 is about 271.5385187739.

Adding to 20021395 its reverse (59312002), we get a palindrome (79333397).

The spelling of 20021395 in words is "twenty million, twenty-one thousand, three hundred ninety-five".