21873631187 has 2 divisors, whose sum is σ = 21873631188. Its totient is φ = 21873631186.

The previous prime is 21873631183. The next prime is 21873631201. The reversal of 21873631187 is 78113637812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21873631187 - 2² = 21873631183 is a prime.

It is not a weakly prime, because it can be changed into another prime (21873631183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936815593 + 10936815594.

It is an arithmetic number, because the mean of its divisors is an integer number (10936815594).

Almost surely, 2^21873631187 is an apocalyptic number.

21873631187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873631187 is an equidigital number, since it uses as much as digits as its factorization.

21873631187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 47.

The spelling of 21873631187 in words is "twenty-one billion, eight hundred seventy-three million, six hundred thirty-one thousand, one hundred eighty-seven".