20618573 has 4 divisors (see below), whose sum is σ = 20650428. Its totient is φ = 20586720.

The previous prime is 20618567. The next prime is 20618593. The reversal of 20618573 is 37581602.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13446889 + 7171684 = 3667^2 + 2678^2 .

It is a cyclic number.

It is not a de Polignac number, because 20618573 - 2¹⁴ = 20602189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20618593) 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, 14936 + ... + 16257.

It is an arithmetic number, because the mean of its divisors is an integer number (5162607).

Almost surely, 2^20618573 is an apocalyptic number.

It is an amenable number.

20618573 is a deficient number, since it is larger than the sum of its proper divisors (31855).

20618573 is an equidigital number, since it uses as much as digits as its factorization.

20618573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31854.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 20618573 is about 4540.7678866024. The cubic root of 20618573 is about 274.2118391256.

The spelling of 20618573 in words is "twenty million, six hundred eighteen thousand, five hundred seventy-three".