20681601 has 4 divisors (see below), whose sum is σ = 27575472. Its totient is φ = 13787732.

The previous prime is 20681579. The next prime is 20681621. The reversal of 20681601 is 10618602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20681601 - 2¹³ = 20673409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20681621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3446931 + ... + 3446936.

It is an arithmetic number, because the mean of its divisors is an integer number (6893868).

Almost surely, 2^20681601 is an apocalyptic number.

It is an amenable number.

20681601 is a deficient number, since it is larger than the sum of its proper divisors (6893871).

20681601 is an equidigital number, since it uses as much as digits as its factorization.

20681601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6893870.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 20681601 is about 4547.7028267027. The cubic root of 20681601 is about 274.4909635679.

The spelling of 20681601 in words is "twenty million, six hundred eighty-one thousand, six hundred one".