21293773187 has 2 divisors, whose sum is σ = 21293773188. Its totient is φ = 21293773186.

The previous prime is 21293773169. The next prime is 21293773201. The reversal of 21293773187 is 78137739212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21293773187 - 2²⁰ = 21292724611 is a prime.

It is not a weakly prime, because it can be changed into another prime (21293773387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10646886593 + 10646886594.

It is an arithmetic number, because the mean of its divisors is an integer number (10646886594).

Almost surely, 2^21293773187 is an apocalyptic number.

21293773187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21293773187 is an equidigital number, since it uses as much as digits as its factorization.

21293773187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 889056, while the sum is 50.

The spelling of 21293773187 in words is "twenty-one billion, two hundred ninety-three million, seven hundred seventy-three thousand, one hundred eighty-seven".