20506912451 has 2 divisors, whose sum is σ = 20506912452. Its totient is φ = 20506912450.

The previous prime is 20506912441. The next prime is 20506912453. The reversal of 20506912451 is 15421960502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20506912451 is a prime.

Together with 20506912453, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20506912453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10253456225 + 10253456226.

It is an arithmetic number, because the mean of its divisors is an integer number (10253456226).

Almost surely, 2^20506912451 is an apocalyptic number.

20506912451 is a deficient number, since it is larger than the sum of its proper divisors (1).

20506912451 is an equidigital number, since it uses as much as digits as its factorization.

20506912451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 35.

The spelling of 20506912451 in words is "twenty billion, five hundred six million, nine hundred twelve thousand, four hundred fifty-one".