17923699021 has 2 divisors, whose sum is σ = 17923699022. Its totient is φ = 17923699020.

The previous prime is 17923698977. The next prime is 17923699109. The reversal of 17923699021 is 12099632971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17268850921 + 654848100 = 131411^2 + 25590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17923699021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17923699121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8961849510 + 8961849511.

It is an arithmetic number, because the mean of its divisors is an integer number (8961849511).

Almost surely, 2^17923699021 is an apocalyptic number.

It is an amenable number.

17923699021 is a deficient number, since it is larger than the sum of its proper divisors (1).

17923699021 is an equidigital number, since it uses as much as digits as its factorization.

17923699021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 367416, while the sum is 49.

The spelling of 17923699021 in words is "seventeen billion, nine hundred twenty-three million, six hundred ninety-nine thousand, twenty-one".