20811042 has 48 divisors (see below), whose sum is σ = 54250560. Its totient is φ = 5632416.

The previous prime is 20811041. The next prime is 20811079. The reversal of 20811042 is 24011802.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20811041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1953 + ... + 6740.

It is an arithmetic number, because the mean of its divisors is an integer number (1130220).

Almost surely, 2^20811042 is an apocalyptic number.

20811042 is an abundant number, since it is smaller than the sum of its proper divisors (33439518).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20811042 is a wasteful number, since it uses less digits than its factorization.

20811042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8727 (or 8724 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 20811042 is about 4561.9120991093. The cubic root of 20811042 is about 275.0624299034.

Adding to 20811042 its reverse (24011802), we get a palindrome (44822844).

The spelling of 20811042 in words is "twenty million, eight hundred eleven thousand, forty-two".