20285643 has 8 divisors (see below), whose sum is σ = 30911488. Its totient is φ = 11591784.

The previous prime is 20285633. The next prime is 20285653. The reversal of 20285643 is 34658202.

It is an interprime number because it is at equal distance from previous prime (20285633) and next prime (20285653).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20285643 - 2⁴ = 20285627 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20285643.

It is not an unprimeable number, because it can be changed into a prime (20285633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 482971 + ... + 483012.

It is an arithmetic number, because the mean of its divisors is an integer number (3863936).

Almost surely, 2^20285643 is an apocalyptic number.

20285643 is a deficient number, since it is larger than the sum of its proper divisors (10625845).

20285643 is an equidigital number, since it uses as much as digits as its factorization.

20285643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965993.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 20285643 is about 4503.9585921720. The cubic root of 20285643 is about 272.7279152611.

The spelling of 20285643 in words is "twenty million, two hundred eighty-five thousand, six hundred forty-three".