20493985 has 4 divisors (see below), whose sum is σ = 24592788. Its totient is φ = 16395184.

The previous prime is 20493983. The next prime is 20493997. The reversal of 20493985 is 58939402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58939402 = 2 ⋅29469701.

It can be written as a sum of positive squares in 2 ways, for example, as 7447441 + 13046544 = 2729^2 + 3612^2 .

It is a cyclic number.

It is not a de Polignac number, because 20493985 - 2¹ = 20493983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20493983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2049394 + ... + 2049403.

It is an arithmetic number, because the mean of its divisors is an integer number (6148197).

Almost surely, 2^20493985 is an apocalyptic number.

It is an amenable number.

20493985 is a deficient number, since it is larger than the sum of its proper divisors (4098803).

20493985 is an equidigital number, since it uses as much as digits as its factorization.

20493985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4098802.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 20493985 is about 4527.0282747074. The cubic root of 20493985 is about 273.6584133755.

The spelling of 20493985 in words is "twenty million, four hundred ninety-three thousand, nine hundred eighty-five".