20581167 has 4 divisors (see below), whose sum is σ = 27441560. Its totient is φ = 13720776.

The previous prime is 20581163. The next prime is 20581189. The reversal of 20581167 is 76118502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20581167 - 2² = 20581163 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20581163) 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 3 ways as a sum of consecutive naturals, for example, 3430192 + ... + 3430197.

It is an arithmetic number, because the mean of its divisors is an integer number (6860390).

Almost surely, 2^20581167 is an apocalyptic number.

20581167 is a deficient number, since it is larger than the sum of its proper divisors (6860393).

20581167 is an equidigital number, since it uses as much as digits as its factorization.

20581167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6860392.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 20581167 is about 4536.6471099260. The cubic root of 20581167 is about 274.0459146598.

Adding to 20581167 its reverse (76118502), we get a palindrome (96699669).

The spelling of 20581167 in words is "twenty million, five hundred eighty-one thousand, one hundred sixty-seven".