18115969 has 2 divisors, whose sum is σ = 18115970. Its totient is φ = 18115968.

The previous prime is 18115967. The next prime is 18115991. The reversal of 18115969 is 96951181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16711744 + 1404225 = 4088^2 + 1185^2 .

It is a cyclic number.

It is not a de Polignac number, because 18115969 - 2¹ = 18115967 is a prime.

It is a super-2 number, since 2×18115969² = 656376665617922, which contains 22 as substring.

Together with 18115967, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18115967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9057984 + 9057985.

It is an arithmetic number, because the mean of its divisors is an integer number (9057985).

Almost surely, 2^18115969 is an apocalyptic number.

It is an amenable number.

18115969 is a deficient number, since it is larger than the sum of its proper divisors (1).

18115969 is an equidigital number, since it uses as much as digits as its factorization.

18115969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 40.

The square root of 18115969 is about 4256.2858221694. The cubic root of 18115969 is about 262.6357586506.

The spelling of 18115969 in words is "eighteen million, one hundred fifteen thousand, nine hundred sixty-nine".