20874181 has 6 divisors (see below), whose sum is σ = 22174610. Its totient is φ = 19646016.

The previous prime is 20874173. The next prime is 20874211. The reversal of 20874181 is 18147802.

It can be written as a sum of positive squares in 3 ways, for example, as 4601025 + 16273156 = 2145^2 + 4034^2 .

It is not a de Polignac number, because 20874181 - 2³ = 20874173 is a prime.

It is a super-2 number, since 2×20874181² = 871462864841522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871181) 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 5 ways as a sum of consecutive naturals, for example, 35826 + ... + 36403.

Almost surely, 2^20874181 is an apocalyptic number.

It is an amenable number.

20874181 is a deficient number, since it is larger than the sum of its proper divisors (1300429).

20874181 is an equidigital number, since it uses as much as digits as its factorization.

20874181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72263 (or 72246 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 20874181 is about 4568.8270923728. The cubic root of 20874181 is about 275.3403213673.

The spelling of 20874181 in words is "twenty million, eight hundred seventy-four thousand, one hundred eighty-one".