20195581 has 8 divisors (see below), whose sum is σ = 23250240. Its totient is φ = 17183328.

The previous prime is 20195579. The next prime is 20195603. The reversal of 20195581 is 18559102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20195581 - 2¹ = 20195579 is a prime.

It is a super-2 number, since 2×20195581² = 815722983855122, 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 (20195521) 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 7 ways as a sum of consecutive naturals, for example, 9571 + ... + 11488.

It is an arithmetic number, because the mean of its divisors is an integer number (2906280).

Almost surely, 2^20195581 is an apocalyptic number.

It is an amenable number.

20195581 is a deficient number, since it is larger than the sum of its proper divisors (3054659).

20195581 is a wasteful number, since it uses less digits than its factorization.

20195581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21203.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 20195581 is about 4493.9493766619. The cubic root of 20195581 is about 272.3237071998.

The spelling of 20195581 in words is "twenty million, one hundred ninety-five thousand, five hundred eighty-one".