20256401 has 16 divisors (see below), whose sum is σ = 23587200. Its totient is φ = 17191680.

The previous prime is 20256391. The next prime is 20256403. The reversal of 20256401 is 10465202.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20256401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20256403) 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 15 ways as a sum of consecutive naturals, for example, 27500 + ... + 28226.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^20256401 is an apocalyptic number.

It is an amenable number.

20256401 is a deficient number, since it is larger than the sum of its proper divisors (3330799).

20256401 is a wasteful number, since it uses less digits than its factorization.

20256401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 904.

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

The square root of 20256401 is about 4500.7111660270. The cubic root of 20256401 is about 272.5968053781.

The spelling of 20256401 in words is "twenty million, two hundred fifty-six thousand, four hundred one".