17972708909 has 2 divisors, whose sum is σ = 17972708910. Its totient is φ = 17972708908.

The previous prime is 17972708899. The next prime is 17972708947. The reversal of 17972708909 is 90980727971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16705562500 + 1267146409 = 129250^2 + 35597^2 .

It is a cyclic number.

It is not a de Polignac number, because 17972708909 - 2⁸ = 17972708653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17972708959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8986354454 + 8986354455.

It is an arithmetic number, because the mean of its divisors is an integer number (8986354455).

Almost surely, 2^17972708909 is an apocalyptic number.

It is an amenable number.

17972708909 is a deficient number, since it is larger than the sum of its proper divisors (1).

17972708909 is an equidigital number, since it uses as much as digits as its factorization.

17972708909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4000752, while the sum is 59.

The spelling of 17972708909 in words is "seventeen billion, nine hundred seventy-two million, seven hundred eight thousand, nine hundred nine".