20256403 has 2 divisors, whose sum is σ = 20256404. Its totient is φ = 20256402.

The previous prime is 20256391. The next prime is 20256407. The reversal of 20256403 is 30465202.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20256403 is a prime.

It is not a weakly prime, because it can be changed into another prime (20256407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10128201 + 10128202.

It is an arithmetic number, because the mean of its divisors is an integer number (10128202).

Almost surely, 2^20256403 is an apocalyptic number.

20256403 is a deficient number, since it is larger than the sum of its proper divisors (1).

20256403 is an equidigital number, since it uses as much as digits as its factorization.

20256403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 20256403 is about 4500.7113882141. The cubic root of 20256403 is about 272.5968143496.

The spelling of 20256403 in words is "twenty million, two hundred fifty-six thousand, four hundred three".