21071712097 has 2 divisors, whose sum is σ = 21071712098. Its totient is φ = 21071712096.

The previous prime is 21071712071. The next prime is 21071712133. The reversal of 21071712097 is 79021717012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11963109376 + 9108602721 = 109376^2 + 95439^2 .

It is a cyclic number.

It is not a de Polignac number, because 21071712097 - 2¹⁵ = 21071679329 is a prime.

It is a super-2 number, since 2×21071712097² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21071712017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10535856048 + 10535856049.

It is an arithmetic number, because the mean of its divisors is an integer number (10535856049).

Almost surely, 2^21071712097 is an apocalyptic number.

It is an amenable number.

21071712097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21071712097 is an equidigital number, since it uses as much as digits as its factorization.

21071712097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12348, while the sum is 37.

The spelling of 21071712097 in words is "twenty-one billion, seventy-one million, seven hundred twelve thousand, ninety-seven".