21099301397 has 2 divisors, whose sum is σ = 21099301398. Its totient is φ = 21099301396.

The previous prime is 21099301357. The next prime is 21099301417. The reversal of 21099301397 is 79310399012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20932013041 + 167288356 = 144679^2 + 12934^2 .

It is a cyclic number.

It is not a de Polignac number, because 21099301397 - 2¹⁰ = 21099300373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21099301357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10549650698 + 10549650699.

It is an arithmetic number, because the mean of its divisors is an integer number (10549650699).

Almost surely, 2^21099301397 is an apocalyptic number.

It is an amenable number.

21099301397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21099301397 is an equidigital number, since it uses as much as digits as its factorization.

21099301397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 91854, while the sum is 44.

The spelling of 21099301397 in words is "twenty-one billion, ninety-nine million, three hundred one thousand, three hundred ninety-seven".