21289561747 has 2 divisors, whose sum is σ = 21289561748. Its totient is φ = 21289561746.

The previous prime is 21289561687. The next prime is 21289561763. The reversal of 21289561747 is 74716598212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21289561747 - 2²³ = 21281173139 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21289561694 and 21289561703.

It is not a weakly prime, because it can be changed into another prime (21289561247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10644780873 + 10644780874.

It is an arithmetic number, because the mean of its divisors is an integer number (10644780874).

Almost surely, 2^21289561747 is an apocalyptic number.

21289561747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21289561747 is an equidigital number, since it uses as much as digits as its factorization.

21289561747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1693440, while the sum is 52.

The spelling of 21289561747 in words is "twenty-one billion, two hundred eighty-nine million, five hundred sixty-one thousand, seven hundred forty-seven".