20861885056247 has 16 divisors (see below), whose sum is σ = 22357854810720. Its totient is φ = 19396851038208.

The previous prime is 20861885056237. The next prime is 20861885056303. The reversal of 20861885056247 is 74265058816802.

It is a cyclic number.

It is not a de Polignac number, because 20861885056247 - 2³⁴ = 20844705187063 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20861885056247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20861885056237) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16079453 + ... + 17328374.

It is an arithmetic number, because the mean of its divisors is an integer number (1397365925670).

Almost surely, 2^{20861885056247} is an apocalyptic number.

20861885056247 is a deficient number, since it is larger than the sum of its proper divisors (1495969754473).

20861885056247 is a wasteful number, since it uses less digits than its factorization.

20861885056247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33408290.

The product of its (nonzero) digits is 51609600, while the sum is 62.

The spelling of 20861885056247 in words is "twenty trillion, eight hundred sixty-one billion, eight hundred eighty-five million, fifty-six thousand, two hundred forty-seven".