20523081 has 4 divisors (see below), whose sum is σ = 27364112. Its totient is φ = 13682052.

The previous prime is 20523077. The next prime is 20523089. The reversal of 20523081 is 18032502.

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 not a de Polignac number, because 20523081 - 2² = 20523077 is a prime.

It is a super-2 number, since 2×20523081² = 842393707465122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20523089) 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, 3420511 + ... + 3420516.

It is an arithmetic number, because the mean of its divisors is an integer number (6841028).

Almost surely, 2^20523081 is an apocalyptic number.

It is an amenable number.

20523081 is a deficient number, since it is larger than the sum of its proper divisors (6841031).

20523081 is an equidigital number, since it uses as much as digits as its factorization.

20523081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6841030.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 20523081 is about 4530.2407220809. The cubic root of 20523081 is about 273.7878594872.

Adding to 20523081 its reverse (18032502), we get a palindrome (38555583).

The spelling of 20523081 in words is "twenty million, five hundred twenty-three thousand, eighty-one".