20515755047 has 2 divisors, whose sum is σ = 20515755048. Its totient is φ = 20515755046.

The previous prime is 20515755017. The next prime is 20515755049. The reversal of 20515755047 is 74055751502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20515755047 - 2¹⁰ = 20515754023 is a prime.

Together with 20515755049, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20515754995 and 20515755013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20515755049) 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, 10257877523 + 10257877524.

It is an arithmetic number, because the mean of its divisors is an integer number (10257877524).

Almost surely, 2^20515755047 is an apocalyptic number.

20515755047 is a deficient number, since it is larger than the sum of its proper divisors (1).

20515755047 is an equidigital number, since it uses as much as digits as its factorization.

20515755047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 245000, while the sum is 41.

The spelling of 20515755047 in words is "twenty billion, five hundred fifteen million, seven hundred fifty-five thousand, forty-seven".