20400289 has 16 divisors (see below), whose sum is σ = 26587008. Its totient is φ = 15190272.

The previous prime is 20400277. The next prime is 20400301. The reversal of 20400289 is 98200402.

It is an interprime number because it is at equal distance from previous prime (20400277) and next prime (20400301).

It is a cyclic number.

It is not a de Polignac number, because 20400289 - 2⁵ = 20400257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20400239) 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, 5047 + ... + 8140.

It is an arithmetic number, because the mean of its divisors is an integer number (1661688).

Almost surely, 2^20400289 is an apocalyptic number.

It is an amenable number.

20400289 is a deficient number, since it is larger than the sum of its proper divisors (6186719).

20400289 is a wasteful number, since it uses less digits than its factorization.

20400289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13224.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 20400289 is about 4516.6679089789. The cubic root of 20400289 is about 273.2407319007.

The spelling of 20400289 in words is "twenty million, four hundred thousand, two hundred eighty-nine".