20905011 has 6 divisors (see below), whose sum is σ = 30196140. Its totient is φ = 13936668.

The previous prime is 20905007. The next prime is 20905033. The reversal of 20905011 is 11050902.

It is not a de Polignac number, because 20905011 - 2² = 20905007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20905051) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1161381 + ... + 1161398.

It is an arithmetic number, because the mean of its divisors is an integer number (5032690).

Almost surely, 2^20905011 is an apocalyptic number.

20905011 is a deficient number, since it is larger than the sum of its proper divisors (9291129).

20905011 is a wasteful number, since it uses less digits than its factorization.

20905011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2322785 (or 2322782 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 20905011 is about 4572.1997987840. The cubic root of 20905011 is about 275.4758087812.

Adding to 20905011 its reverse (11050902), we get a palindrome (31955913).

The spelling of 20905011 in words is "twenty million, nine hundred five thousand, eleven".