20217601 has 4 divisors (see below), whose sum is σ = 20473600. Its totient is φ = 19961604.

The previous prime is 20217583. The next prime is 20217619. The reversal of 20217601 is 10671202.

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, and also an emirpimes, since its reverse is a distinct semiprime: 10671202 = 2 ⋅5335601.

It is an interprime number because it is at equal distance from previous prime (20217583) and next prime (20217619).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20217601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20217101) 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, 127881 + ... + 128038.

It is an arithmetic number, because the mean of its divisors is an integer number (5118400).

Almost surely, 2^20217601 is an apocalyptic number.

It is an amenable number.

20217601 is a deficient number, since it is larger than the sum of its proper divisors (255999).

20217601 is an equidigital number, since it uses as much as digits as its factorization.

20217601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255998.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 20217601 is about 4496.3986700470. The cubic root of 20217601 is about 272.4226461694.

Adding to 20217601 its reverse (10671202), we get a palindrome (30888803).

The spelling of 20217601 in words is "twenty million, two hundred seventeen thousand, six hundred one".