20581601 has 8 divisors (see below), whose sum is σ = 20827560. Its totient is φ = 20337408.

The previous prime is 20581571. The next prime is 20581607. The reversal of 20581601 is 10618502.

It can be written as a sum of positive squares in 4 ways, for example, as 15376 + 20566225 = 124^2 + 4535^2 .

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 20581601 - 2¹⁸ = 20319457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20581607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52715 + ... + 53103.

It is an arithmetic number, because the mean of its divisors is an integer number (2603445).

Almost surely, 2^20581601 is an apocalyptic number.

It is an amenable number.

20581601 is a deficient number, since it is larger than the sum of its proper divisors (245959).

20581601 is a wasteful number, since it uses less digits than its factorization.

20581601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 883.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 20581601 is about 4536.6949423562. The cubic root of 20581601 is about 274.0478409369.

The spelling of 20581601 in words is "twenty million, five hundred eighty-one thousand, six hundred one".