20512231 has 4 divisors (see below), whose sum is σ = 20616552. Its totient is φ = 20407912.

The previous prime is 20512223. The next prime is 20512241. The reversal of 20512231 is 13221502.

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

It is a cyclic number.

It is not a de Polignac number, because 20512231 - 2³ = 20512223 is a prime.

It is a super-2 number, since 2×20512231² = 841503241194722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20512201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51865 + ... + 52258.

It is an arithmetic number, because the mean of its divisors is an integer number (5154138).

Almost surely, 2^20512231 is an apocalyptic number.

20512231 is a deficient number, since it is larger than the sum of its proper divisors (104321).

20512231 is a wasteful number, since it uses less digits than its factorization.

20512231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104320.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20512231 is about 4529.0430556576. The cubic root of 20512231 is about 273.7396028939.

Adding to 20512231 its reverse (13221502), we get a palindrome (33733733).

The spelling of 20512231 in words is "twenty million, five hundred twelve thousand, two hundred thirty-one".