18907829321 has 2 divisors, whose sum is σ = 18907829322. Its totient is φ = 18907829320.

The previous prime is 18907829279. The next prime is 18907829399. The reversal of 18907829321 is 12392870981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18836190025 + 71639296 = 137245^2 + 8464^2 .

It is a cyclic number.

It is not a de Polignac number, because 18907829321 - 2¹⁰ = 18907828297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18907829321.

It is not a weakly prime, because it can be changed into another prime (18907829921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9453914660 + 9453914661.

It is an arithmetic number, because the mean of its divisors is an integer number (9453914661).

Almost surely, 2^18907829321 is an apocalyptic number.

It is an amenable number.

18907829321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18907829321 is an equidigital number, since it uses as much as digits as its factorization.

18907829321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 50.

The spelling of 18907829321 in words is "eighteen billion, nine hundred seven million, eight hundred twenty-nine thousand, three hundred twenty-one".