20017860251 has 8 divisors (see below), whose sum is σ = 20073590208. Its totient is φ = 19962160000.

The previous prime is 20017860209. The next prime is 20017860257. The reversal of 20017860251 is 15206871002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20017860251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20017860257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2285741 + ... + 2294481.

It is an arithmetic number, because the mean of its divisors is an integer number (2509198776).

Almost surely, 2^20017860251 is an apocalyptic number.

20017860251 is a deficient number, since it is larger than the sum of its proper divisors (55729957).

20017860251 is an equidigital number, since it uses as much as digits as its factorization.

20017860251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14853.

The product of its (nonzero) digits is 6720, while the sum is 32.

The spelling of 20017860251 in words is "twenty billion, seventeen million, eight hundred sixty thousand, two hundred fifty-one".