20481553 has 2 divisors, whose sum is σ = 20481554. Its totient is φ = 20481552.

The previous prime is 20481541. The next prime is 20481557. The reversal of 20481553 is 35518402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11068929 + 9412624 = 3327^2 + 3068^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20481553 is a prime.

It is not a weakly prime, because it can be changed into another prime (20481557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10240776 + 10240777.

It is an arithmetic number, because the mean of its divisors is an integer number (10240777).

Almost surely, 2^20481553 is an apocalyptic number.

It is an amenable number.

20481553 is a deficient number, since it is larger than the sum of its proper divisors (1).

20481553 is an equidigital number, since it uses as much as digits as its factorization.

20481553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 20481553 is about 4525.6549802211. The cubic root of 20481553 is about 273.6030668993.

Adding to 20481553 its reverse (35518402), we get a palindrome (55999955).

The spelling of 20481553 in words is "twenty million, four hundred eighty-one thousand, five hundred fifty-three".