20611131 has 4 divisors (see below), whose sum is σ = 27481512. Its totient is φ = 13740752.

The previous prime is 20611127. The next prime is 20611133. The reversal of 20611131 is 13111602.

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 20611131 - 2² = 20611127 is a prime.

It is a super-2 number, since 2×20611131² = 849637442198322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20611131.

It is not an unprimeable number, because it can be changed into a prime (20611133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3435186 + ... + 3435191.

It is an arithmetic number, because the mean of its divisors is an integer number (6870378).

Almost surely, 2^20611131 is an apocalyptic number.

20611131 is a deficient number, since it is larger than the sum of its proper divisors (6870381).

20611131 is an equidigital number, since it uses as much as digits as its factorization.

20611131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6870380.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 20611131 is about 4539.9483477238. The cubic root of 20611131 is about 274.1788441154.

Adding to 20611131 its reverse (13111602), we get a palindrome (33722733).

The spelling of 20611131 in words is "twenty million, six hundred eleven thousand, one hundred thirty-one".