20609811 has 6 divisors (see below), whose sum is σ = 29769740. Its totient is φ = 13739868.

The previous prime is 20609801. The next prime is 20609843. The reversal of 20609811 is 11890602.

It is not a de Polignac number, because 20609811 - 2⁵ = 20609779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20609801) 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, 1144981 + ... + 1144998.

Almost surely, 2^20609811 is an apocalyptic number.

20609811 is a deficient number, since it is larger than the sum of its proper divisors (9159929).

20609811 is a wasteful number, since it uses less digits than its factorization.

20609811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2289985 (or 2289982 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 20609811 is about 4539.8029692928. The cubic root of 20609811 is about 274.1729909060.

The spelling of 20609811 in words is "twenty million, six hundred nine thousand, eight hundred eleven".