20056421 has 16 divisors (see below), whose sum is σ = 25619328. Its totient is φ = 15244800.

The previous prime is 20056403. The next prime is 20056423. The reversal of 20056421 is 12465002.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20056421 - 2¹⁸ = 19794277 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20056393 and 20056402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20056423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20 + ... + 6333.

It is an arithmetic number, because the mean of its divisors is an integer number (1601208).

Almost surely, 2^20056421 is an apocalyptic number.

It is an amenable number.

20056421 is a deficient number, since it is larger than the sum of its proper divisors (5562907).

20056421 is a wasteful number, since it uses less digits than its factorization.

20056421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6412.

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

The square root of 20056421 is about 4478.4395719938. The cubic root of 20056421 is about 271.6967722710.

The spelling of 20056421 in words is "twenty million, fifty-six thousand, four hundred twenty-one".