20117621455247 has 2 divisors, whose sum is σ = 20117621455248. Its totient is φ = 20117621455246.

The previous prime is 20117621455237. The next prime is 20117621455277. The reversal of 20117621455247 is 74255412671102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20117621455247 - 2²² = 20117617260943 is a prime.

It is a super-2 number, since 2×20117621455247² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20117621455237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10058810727623 + 10058810727624.

It is an arithmetic number, because the mean of its divisors is an integer number (10058810727624).

Almost surely, 2^{20117621455247} is an apocalyptic number.

20117621455247 is a deficient number, since it is larger than the sum of its proper divisors (1).

20117621455247 is an equidigital number, since it uses as much as digits as its factorization.

20117621455247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 940800, while the sum is 47.

The spelling of 20117621455247 in words is "twenty trillion, one hundred seventeen billion, six hundred twenty-one million, four hundred fifty-five thousand, two hundred forty-seven".