21099079637 has 2 divisors, whose sum is σ = 21099079638. Its totient is φ = 21099079636.

The previous prime is 21099079609. The next prime is 21099079643. The reversal of 21099079637 is 73697099012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19872258961 + 1226820676 = 140969^2 + 35026^2 .

It is a cyclic number.

It is not a de Polignac number, because 21099079637 - 2¹⁰ = 21099078613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21099072637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10549539818 + 10549539819.

It is an arithmetic number, because the mean of its divisors is an integer number (10549539819).

Almost surely, 2^21099079637 is an apocalyptic number.

It is an amenable number.

21099079637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21099079637 is an equidigital number, since it uses as much as digits as its factorization.

21099079637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1285956, while the sum is 53.

The spelling of 21099079637 in words is "twenty-one billion, ninety-nine million, seventy-nine thousand, six hundred thirty-seven".