20065421 has 4 divisors (see below), whose sum is σ = 20100192. Its totient is φ = 20030652.

The previous prime is 20065417. The next prime is 20065427. The reversal of 20065421 is 12456002.

It is a happy number.

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 20065421 - 2² = 20065417 is a prime.

It is a super-2 number, since 2×20065421² = 805242239814482, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20065393 and 20065402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20065427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16505 + ... + 17678.

It is an arithmetic number, because the mean of its divisors is an integer number (5025048).

Almost surely, 2^20065421 is an apocalyptic number.

It is an amenable number.

20065421 is a deficient number, since it is larger than the sum of its proper divisors (34771).

20065421 is an equidigital number, since it uses as much as digits as its factorization.

20065421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34770.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20065421 is about 4479.4442735679. Note that the first 3 decimals coincide. The cubic root of 20065421 is about 271.7374060624.

The spelling of 20065421 in words is "twenty million, sixty-five thousand, four hundred twenty-one".