20188011 has 16 divisors (see below), whose sum is σ = 27641088. Its totient is φ = 13101600.

The previous prime is 20188009. The next prime is 20188019. The reversal of 20188011 is 11088102.

It is not a de Polignac number, because 20188011 - 2¹ = 20188009 is a prime.

It is a super-2 number, since 2×20188011² = 815111576272242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20188019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19066 + ... + 20096.

It is an arithmetic number, because the mean of its divisors is an integer number (1727568).

Almost surely, 2^20188011 is an apocalyptic number.

20188011 is a deficient number, since it is larger than the sum of its proper divisors (7453077).

20188011 is a wasteful number, since it uses less digits than its factorization.

20188011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202.

The product of its (nonzero) digits is 128, while the sum is 21.

The square root of 20188011 is about 4493.1070541442. The cubic root of 20188011 is about 272.2896775097.

Subtracting from 20188011 its reverse (11088102), we obtain a palindrome (9099909).

The spelling of 20188011 in words is "twenty million, one hundred eighty-eight thousand, eleven".