18969869 has 2 divisors, whose sum is σ = 18969870. Its totient is φ = 18969868.

The previous prime is 18969817. The next prime is 18969877. The reversal of 18969869 is 96896981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18966025 + 3844 = 4355^2 + 62^2 .

It is a cyclic number.

It is not a de Polignac number, because 18969869 - 2¹² = 18965773 is a prime.

It is a super-2 number, since 2×18969869² = 719711859754322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18969169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9484934 + 9484935.

It is an arithmetic number, because the mean of its divisors is an integer number (9484935).

Almost surely, 2^18969869 is an apocalyptic number.

It is an amenable number.

18969869 is a deficient number, since it is larger than the sum of its proper divisors (1).

18969869 is an equidigital number, since it uses as much as digits as its factorization.

18969869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1679616, while the sum is 56.

The square root of 18969869 is about 4355.4413094427. The cubic root of 18969869 is about 266.6990347863.

The spelling of 18969869 in words is "eighteen million, nine hundred sixty-nine thousand, eight hundred sixty-nine".