21787112827 has 2 divisors, whose sum is σ = 21787112828. Its totient is φ = 21787112826.

The previous prime is 21787112803. The next prime is 21787112833. The reversal of 21787112827 is 72821178712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21787112827 - 2¹⁵ = 21787080059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21787112857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10893556413 + 10893556414.

It is an arithmetic number, because the mean of its divisors is an integer number (10893556414).

Almost surely, 2^21787112827 is an apocalyptic number.

21787112827 is a deficient number, since it is larger than the sum of its proper divisors (1).

21787112827 is an equidigital number, since it uses as much as digits as its factorization.

21787112827 is an evil number, because the sum of its binary digits is even.

The product of its digits is 175616, while the sum is 46.

The spelling of 21787112827 in words is "twenty-one billion, seven hundred eighty-seven million, one hundred twelve thousand, eight hundred twenty-seven".