20813844187 has 2 divisors, whose sum is σ = 20813844188. Its totient is φ = 20813844186.

The previous prime is 20813844151. The next prime is 20813844193. The reversal of 20813844187 is 78144831802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20813844187 - 2⁷ = 20813844059 is a prime.

It is a super-2 number, since 2×20813844187² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20813844287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10406922093 + 10406922094.

It is an arithmetic number, because the mean of its divisors is an integer number (10406922094).

Almost surely, 2^20813844187 is an apocalyptic number.

20813844187 is a deficient number, since it is larger than the sum of its proper divisors (1).

20813844187 is an equidigital number, since it uses as much as digits as its factorization.

20813844187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 344064, while the sum is 46.

The spelling of 20813844187 in words is "twenty billion, eight hundred thirteen million, eight hundred forty-four thousand, one hundred eighty-seven".