21071104997 has 2 divisors, whose sum is σ = 21071104998. Its totient is φ = 21071104996.

The previous prime is 21071104993. The next prime is 21071105047. The reversal of 21071104997 is 79940117012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21068812801 + 2292196 = 145151^2 + 1514^2 .

It is a cyclic number.

It is not a de Polignac number, because 21071104997 - 2² = 21071104993 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21071104993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10535552498 + 10535552499.

It is an arithmetic number, because the mean of its divisors is an integer number (10535552499).

Almost surely, 2^21071104997 is an apocalyptic number.

It is an amenable number.

21071104997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21071104997 is an equidigital number, since it uses as much as digits as its factorization.

21071104997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31752, while the sum is 41.

The spelling of 21071104997 in words is "twenty-one billion, seventy-one million, one hundred four thousand, nine hundred ninety-seven".