20518011 has 12 divisors (see below), whose sum is σ = 29713320. Its totient is φ = 13643520.

The previous prime is 20517989. The next prime is 20518019. The reversal of 20518011 is 11081502.

It is not a de Polignac number, because 20518011 - 2⁶ = 20517947 is a prime.

It is a super-2 number, since 2×20518011² = 841977550792242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20518019) 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 11 ways as a sum of consecutive naturals, for example, 1051 + ... + 6491.

It is an arithmetic number, because the mean of its divisors is an integer number (2476110).

Almost surely, 2^20518011 is an apocalyptic number.

20518011 is a deficient number, since it is larger than the sum of its proper divisors (9195309).

20518011 is a wasteful number, since it uses less digits than its factorization.

20518011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5866 (or 5863 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 20518011 is about 4529.6811146040. The cubic root of 20518011 is about 273.7653122104.

Adding to 20518011 its reverse (11081502), we get a palindrome (31599513).

The spelling of 20518011 in words is "twenty million, five hundred eighteen thousand, eleven".