20531255497 has 2 divisors, whose sum is σ = 20531255498. Its totient is φ = 20531255496.

The previous prime is 20531255491. The next prime is 20531255501. The reversal of 20531255497 is 79455213502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20509390521 + 21864976 = 143211^2 + 4676^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20531255497 is a prime.

It is not a weakly prime, because it can be changed into another prime (20531255491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10265627748 + 10265627749.

It is an arithmetic number, because the mean of its divisors is an integer number (10265627749).

Almost surely, 2^20531255497 is an apocalyptic number.

It is an amenable number.

20531255497 is a deficient number, since it is larger than the sum of its proper divisors (1).

20531255497 is an equidigital number, since it uses as much as digits as its factorization.

20531255497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378000, while the sum is 43.

Adding to 20531255497 its reverse (79455213502), we get a palindrome (99986468999).

The spelling of 20531255497 in words is "twenty billion, five hundred thirty-one million, two hundred fifty-five thousand, four hundred ninety-seven".