20525431 has 2 divisors, whose sum is σ = 20525432. Its totient is φ = 20525430.

The previous prime is 20525429. The next prime is 20525437. The reversal of 20525431 is 13452502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20525431 - 2¹ = 20525429 is a prime.

It is a super-2 number, since 2×20525431² = 842586635471522, which contains 22 as substring.

Together with 20525429, it forms a pair of twin primes.

It is the 4531-st Hogben number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20525437) by changing a digit.

It is a nontrivial repunit in base 4530.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10262715 + 10262716.

It is an arithmetic number, because the mean of its divisors is an integer number (10262716).

Almost surely, 2^20525431 is an apocalyptic number.

20525431 is a deficient number, since it is larger than the sum of its proper divisors (1).

20525431 is an equidigital number, since it uses as much as digits as its factorization.

20525431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 20525431 is about 4530.5000827723. The cubic root of 20525431 is about 273.7983091352.

Adding to 20525431 its reverse (13452502), we get a palindrome (33977933).

The spelling of 20525431 in words is "twenty million, five hundred twenty-five thousand, four hundred thirty-one".