20581253 has 24 divisors (see below), whose sum is σ = 26433984. Its totient is φ = 15696120.

The previous prime is 20581243. The next prime is 20581259. The reversal of 20581253 is 35218502.

It is not a de Polignac number, because 20581253 - 2⁶ = 20581189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20581259) 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 23 ways as a sum of consecutive naturals, for example, 437876 + ... + 437922.

It is an arithmetic number, because the mean of its divisors is an integer number (1101416).

Almost surely, 2^20581253 is an apocalyptic number.

It is an amenable number.

20581253 is a deficient number, since it is larger than the sum of its proper divisors (5852731).

20581253 is an frugal number, since it uses more digits than its factorization.

20581253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 20581253 is about 4536.6565882817. The cubic root of 20581253 is about 274.0462963666.

Adding to 20581253 its reverse (35218502), we get a palindrome (55799755).

The spelling of 20581253 in words is "twenty million, five hundred eighty-one thousand, two hundred fifty-three".