20065921 has 4 divisors (see below), whose sum is σ = 20320000. Its totient is φ = 19811844.

The previous prime is 20065909. The next prime is 20065931. The reversal of 20065921 is 12956002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20065921 - 2¹³ = 20057729 is a prime.

It is the 4480-th Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20065931) by changing a digit.

It is a nontrivial repunit in base 4479.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126921 + ... + 127078.

It is an arithmetic number, because the mean of its divisors is an integer number (5080000).

Almost surely, 2^20065921 is an apocalyptic number.

It is an amenable number.

20065921 is a deficient number, since it is larger than the sum of its proper divisors (254079).

20065921 is an equidigital number, since it uses as much as digits as its factorization.

20065921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254078.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20065921 is about 4479.5000837147. The cubic root of 20065921 is about 271.7396631389.

The spelling of 20065921 in words is "twenty million, sixty-five thousand, nine hundred twenty-one".