21246408187 has 2 divisors, whose sum is σ = 21246408188. Its totient is φ = 21246408186.

The previous prime is 21246408181. The next prime is 21246408199. The reversal of 21246408187 is 78180464212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21246408187 - 2¹⁹ = 21245883899 is a prime.

It is not a weakly prime, because it can be changed into another prime (21246408181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10623204093 + 10623204094.

It is an arithmetic number, because the mean of its divisors is an integer number (10623204094).

Almost surely, 2^21246408187 is an apocalyptic number.

21246408187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21246408187 is an equidigital number, since it uses as much as digits as its factorization.

21246408187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172032, while the sum is 43.

The spelling of 21246408187 in words is "twenty-one billion, two hundred forty-six million, four hundred eight thousand, one hundred eighty-seven".