20705853 has 8 divisors (see below), whose sum is σ = 31551808. Its totient is φ = 11831904.

The previous prime is 20705849. The next prime is 20705863. The reversal of 20705853 is 35850702.

It is a happy number.

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

It is not a de Polignac number, because 20705853 - 2² = 20705849 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 20705853.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20705863) 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, 492976 + ... + 493017.

It is an arithmetic number, because the mean of its divisors is an integer number (3943976).

Almost surely, 2^20705853 is an apocalyptic number.

It is an amenable number.

20705853 is a deficient number, since it is larger than the sum of its proper divisors (10845955).

20705853 is an equidigital number, since it uses as much as digits as its factorization.

20705853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986003.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 20705853 is about 4550.3684466206. The cubic root of 20705853 is about 274.5982143635.

The spelling of 20705853 in words is "twenty million, seven hundred five thousand, eight hundred fifty-three".