20113511 has 4 divisors (see below), whose sum is σ = 21942024. Its totient is φ = 18285000.

The previous prime is 20113507. The next prime is 20113537. The reversal of 20113511 is 11531102.

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 20113511 - 2² = 20113507 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 (20110511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914240 + ... + 914261.

It is an arithmetic number, because the mean of its divisors is an integer number (5485506).

Almost surely, 2^20113511 is an apocalyptic number.

20113511 is a deficient number, since it is larger than the sum of its proper divisors (1828513).

20113511 is a wasteful number, since it uses less digits than its factorization.

20113511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1828512.

The product of its (nonzero) digits is 30, while the sum is 14.

The square root of 20113511 is about 4484.8089145470. The cubic root of 20113511 is about 271.9543202918.

Adding to 20113511 its reverse (11531102), we get a palindrome (31644613).

The spelling of 20113511 in words is "twenty million, one hundred thirteen thousand, five hundred eleven".