20256889 has 2 divisors, whose sum is σ = 20256890. Its totient is φ = 20256888.

The previous prime is 20256853. The next prime is 20256931. The reversal of 20256889 is 98865202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 6889 = 4500^2 + 83^2 .

It is a cyclic number.

It is not a de Polignac number, because 20256889 - 2⁹ = 20256377 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20256589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10128444 + 10128445.

It is an arithmetic number, because the mean of its divisors is an integer number (10128445).

Almost surely, 2^20256889 is an apocalyptic number.

It is an amenable number.

20256889 is a deficient number, since it is larger than the sum of its proper divisors (1).

20256889 is an equidigital number, since it uses as much as digits as its factorization.

20256889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 20256889 is about 4500.7653793549. The cubic root of 20256889 is about 272.5989944174.

It can be divided in two parts, 2025 and 6889, that multiplied together give a square (13950225 = 3735²).

The spelling of 20256889 in words is "twenty million, two hundred fifty-six thousand, eight hundred eighty-nine".