17942989 has 2 divisors, whose sum is σ = 17942990. Its totient is φ = 17942988.

The previous prime is 17942987. The next prime is 17942999. The reversal of 17942989 is 98924971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13286025 + 4656964 = 3645^2 + 2158^2 .

It is an emirp because it is prime and its reverse (98924971) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 17942989 - 2¹ = 17942987 is a prime.

Together with 17942987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17942983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8971494 + 8971495.

It is an arithmetic number, because the mean of its divisors is an integer number (8971495).

Almost surely, 2^17942989 is an apocalyptic number.

It is an amenable number.

17942989 is a deficient number, since it is larger than the sum of its proper divisors (1).

17942989 is an equidigital number, since it uses as much as digits as its factorization.

17942989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 49.

The square root of 17942989 is about 4235.9165478088. The cubic root of 17942989 is about 261.7971595914.

The spelling of 17942989 in words is "seventeen million, nine hundred forty-two thousand, nine hundred eighty-nine".