20505411 has 6 divisors (see below), whose sum is σ = 29618940. Its totient is φ = 13670268.

The previous prime is 20505409. The next prime is 20505431. The reversal of 20505411 is 11450502.

It is not a de Polignac number, because 20505411 - 2¹ = 20505409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20505431) 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, 1139181 + ... + 1139198.

It is an arithmetic number, because the mean of its divisors is an integer number (4936490).

Almost surely, 2^20505411 is an apocalyptic number.

20505411 is a deficient number, since it is larger than the sum of its proper divisors (9113529).

20505411 is a wasteful number, since it uses less digits than its factorization.

20505411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278385 (or 2278382 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 20505411 is about 4528.2900746308. The cubic root of 20505411 is about 273.7092614676.

Adding to 20505411 its reverse (11450502), we get a palindrome (31955913).

The spelling of 20505411 in words is "twenty million, five hundred five thousand, four hundred eleven".