20117635721551 has 8 divisors (see below), whose sum is σ = 20311316207424. Its totient is φ = 19924229767680.

The previous prime is 20117635721473. The next prime is 20117635721567. The reversal of 20117635721551 is 15512753671102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20117635721551 - 2³⁹ = 19567879907663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20117635721581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68485735 + ... + 68778856.

It is an arithmetic number, because the mean of its divisors is an integer number (2538914525928).

Almost surely, 2^{20117635721551} is an apocalyptic number.

20117635721551 is a deficient number, since it is larger than the sum of its proper divisors (193680485873).

20117635721551 is a wasteful number, since it uses less digits than its factorization.

20117635721551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137266001.

The product of its (nonzero) digits is 441000, while the sum is 46.

The spelling of 20117635721551 in words is "twenty trillion, one hundred seventeen billion, six hundred thirty-five million, seven hundred twenty-one thousand, five hundred fifty-one".