20523881 has 4 divisors (see below), whose sum is σ = 23455872. Its totient is φ = 17591892.

The previous prime is 20523869. The next prime is 20523887. The reversal of 20523881 is 18832502.

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 20523881 - 2⁶ = 20523817 is a prime.

It is a super-2 number, since 2×20523881² = 842459382604322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20523887) 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 3 ways as a sum of consecutive naturals, for example, 1465985 + ... + 1465998.

It is an arithmetic number, because the mean of its divisors is an integer number (5863968).

Almost surely, 2^20523881 is an apocalyptic number.

It is an amenable number.

20523881 is a deficient number, since it is larger than the sum of its proper divisors (2931991).

20523881 is an equidigital number, since it uses as much as digits as its factorization.

20523881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2931990.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 20523881 is about 4530.3290167492. The cubic root of 20523881 is about 273.7914169037.

The spelling of 20523881 in words is "twenty million, five hundred twenty-three thousand, eight hundred eighty-one".