20712005 has 4 divisors (see below), whose sum is σ = 24854412. Its totient is φ = 16569600.

The previous prime is 20711987. The next prime is 20712019. The reversal of 20712005 is 50021702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50021702 = 2 ⋅25010851.

It can be written as a sum of positive squares in 2 ways, for example, as 14371681 + 6340324 = 3791^2 + 2518^2 .

It is not a de Polignac number, because 20712005 - 2⁶ = 20711941 is a prime.

It is a super-2 number, since 2×20712005² = 857974302240050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2071196 + ... + 2071205.

It is an arithmetic number, because the mean of its divisors is an integer number (6213603).

Almost surely, 2^20712005 is an apocalyptic number.

It is an amenable number.

20712005 is a deficient number, since it is larger than the sum of its proper divisors (4142407).

20712005 is an equidigital number, since it uses as much as digits as its factorization.

20712005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4142406.

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 20712005 is about 4551.0443856328. The cubic root of 20712005 is about 274.6254073337.

Adding to 20712005 its reverse (50021702), we get a palindrome (70733707).

The spelling of 20712005 in words is "twenty million, seven hundred twelve thousand, five".