20523617 has 4 divisors (see below), whose sum is σ = 20533680. Its totient is φ = 20513556.

The previous prime is 20523611. The next prime is 20523623. The reversal of 20523617 is 71632502.

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 a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (20523611) and next prime (20523623).

It is a cyclic number.

It is not a de Polignac number, because 20523617 - 2⁸ = 20523361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20523611) 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 3 ways as a sum of consecutive naturals, for example, 767 + ... + 6452.

It is an arithmetic number, because the mean of its divisors is an integer number (5133420).

Almost surely, 2^20523617 is an apocalyptic number.

It is an amenable number.

20523617 is a deficient number, since it is larger than the sum of its proper divisors (10063).

20523617 is an equidigital number, since it uses as much as digits as its factorization.

20523617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10062.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 20523617 is about 4530.2998796989. The cubic root of 20523617 is about 273.7902429665.

The spelling of 20523617 in words is "twenty million, five hundred twenty-three thousand, six hundred seventeen".