20393857 has 4 divisors (see below), whose sum is σ = 22247856. Its totient is φ = 18539860.

The previous prime is 20393839. The next prime is 20393861. The reversal of 20393857 is 75839302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20393857 - 2⁷ = 20393729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20399857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 926983 + ... + 927004.

It is an arithmetic number, because the mean of its divisors is an integer number (5561964).

Almost surely, 2^20393857 is an apocalyptic number.

It is an amenable number.

20393857 is a deficient number, since it is larger than the sum of its proper divisors (1853999).

20393857 is a wasteful number, since it uses less digits than its factorization.

20393857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1853998.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 20393857 is about 4515.9558235217. The cubic root of 20393857 is about 273.2120122238.

The spelling of 20393857 in words is "twenty million, three hundred ninety-three thousand, eight hundred fifty-seven".