20539973 has 4 divisors (see below), whose sum is σ = 20551008. Its totient is φ = 20528940.

The previous prime is 20539963. The next prime is 20539979. The reversal of 20539973 is 37993502.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20539973 - 2⁴ = 20539957 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 (20539979) 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, 1961 + ... + 6702.

It is an arithmetic number, because the mean of its divisors is an integer number (5137752).

Almost surely, 2^20539973 is an apocalyptic number.

It is an amenable number.

20539973 is a deficient number, since it is larger than the sum of its proper divisors (11035).

20539973 is an equidigital number, since it uses as much as digits as its factorization.

20539973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11034.

The product of its (nonzero) digits is 51030, while the sum is 38.

The square root of 20539973 is about 4532.1046987024. The cubic root of 20539973 is about 273.8629547137.

It can be divided in two parts, 20539 and 973, that added together give a palindrome (21512).

The spelling of 20539973 in words is "twenty million, five hundred thirty-nine thousand, nine hundred seventy-three".