20255421 has 16 divisors (see below), whose sum is σ = 27604800. Its totient is φ = 13208448.

The previous prime is 20255413. The next prime is 20255423. The reversal of 20255421 is 12455202.

It is a happy number.

It is not a de Polignac number, because 20255421 - 2³ = 20255413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20255423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28215 + ... + 28923.

It is an arithmetic number, because the mean of its divisors is an integer number (1725300).

Almost surely, 2^20255421 is an apocalyptic number.

It is an amenable number.

20255421 is a deficient number, since it is larger than the sum of its proper divisors (7349379).

20255421 is a wasteful number, since it uses less digits than its factorization.

20255421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 20255421 is about 4500.6022930270. The cubic root of 20255421 is about 272.5924092504.

The spelling of 20255421 in words is "twenty million, two hundred fifty-five thousand, four hundred twenty-one".