20615503602551 has 48 divisors (see below), whose sum is σ = 25840736256384. Its totient is φ = 16280727936000.

The previous prime is 20615503602541. The next prime is 20615503602587. The reversal of 20615503602551 is 15520630551602.

It is a de Polignac number, because none of the positive numbers 2^k-20615503602551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20615503602499 and 20615503602508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20615503602541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 422242721 + ... + 422291541.

It is an arithmetic number, because the mean of its divisors is an integer number (538348672008).

Almost surely, 2^{20615503602551} is an apocalyptic number.

20615503602551 is a deficient number, since it is larger than the sum of its proper divisors (5225232653833).

20615503602551 is a wasteful number, since it uses less digits than its factorization.

20615503602551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64664 (or 64653 counting only the distinct ones).

The product of its (nonzero) digits is 270000, while the sum is 41.

The spelling of 20615503602551 in words is "twenty trillion, six hundred fifteen billion, five hundred three million, six hundred two thousand, five hundred fifty-one".