20842170 has 32 divisors (see below), whose sum is σ = 52964928. Its totient is φ = 5230848.

The previous prime is 20842169. The next prime is 20842177. The reversal of 20842170 is 7124802.

It is a self number, because there is not a number n which added to its sum of digits gives 20842170.

It is not an unprimeable number, because it can be changed into a prime (20842177) 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 15 ways as a sum of consecutive naturals, for example, 19924 + ... + 20943.

It is an arithmetic number, because the mean of its divisors is an integer number (1655154).

Almost surely, 2^20842170 is an apocalyptic number.

20842170 is an abundant number, since it is smaller than the sum of its proper divisors (32122758).

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

20842170 is a wasteful number, since it uses less digits than its factorization.

20842170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40894.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20842170 is about 4565.3225515838. The cubic root of 20842170 is about 275.1995026159.

Adding to 20842170 its reverse (7124802), we get a palindrome (27966972).

It can be divided in two parts, 20842 and 170, that added together give a palindrome (21012).

The spelling of 20842170 in words is "twenty million, eight hundred forty-two thousand, one hundred seventy".