20840190187 has 2 divisors, whose sum is σ = 20840190188. Its totient is φ = 20840190186.

The previous prime is 20840190181. The next prime is 20840190211. The reversal of 20840190187 is 78109104802.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20840190187 - 2²³ = 20831801579 is a prime.

It is not a weakly prime, because it can be changed into another prime (20840190181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10420095093 + 10420095094.

It is an arithmetic number, because the mean of its divisors is an integer number (10420095094).

Almost surely, 2^20840190187 is an apocalyptic number.

20840190187 is a deficient number, since it is larger than the sum of its proper divisors (1).

20840190187 is an equidigital number, since it uses as much as digits as its factorization.

20840190187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 40.

Adding to 20840190187 its reverse (78109104802), we get a palindrome (98949294989).

The spelling of 20840190187 in words is "twenty billion, eight hundred forty million, one hundred ninety thousand, one hundred eighty-seven".