21741569851 has 2 divisors, whose sum is σ = 21741569852. Its totient is φ = 21741569850.

The previous prime is 21741569821. The next prime is 21741569873. The reversal of 21741569851 is 15896514712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21741569851 - 2¹⁷ = 21741438779 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21741569795 and 21741569804.

It is not a weakly prime, because it can be changed into another prime (21741569821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870784925 + 10870784926.

It is an arithmetic number, because the mean of its divisors is an integer number (10870784926).

Almost surely, 2^21741569851 is an apocalyptic number.

21741569851 is a deficient number, since it is larger than the sum of its proper divisors (1).

21741569851 is an equidigital number, since it uses as much as digits as its factorization.

21741569851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 49.

The spelling of 21741569851 in words is "twenty-one billion, seven hundred forty-one million, five hundred sixty-nine thousand, eight hundred fifty-one".