1868138369 has 4 divisors (see below), whose sum is σ = 1868445360. Its totient is φ = 1867831380.

The previous prime is 1868138357. The next prime is 1868138411. The reversal of 1868138369 is 9638318681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9638318681 = 40897 ⋅235673.

It is a cyclic number.

It is not a de Polignac number, because 1868138369 - 2⁸ = 1868138113 is a prime.

It is a super-2 number, since 2×1868138369² = 6979881931459960322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1868138369.

It is not an unprimeable number, because it can be changed into a prime (1868138869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144179 + ... + 156600.

It is an arithmetic number, because the mean of its divisors is an integer number (467111340).

Almost surely, 2^1868138369 is an apocalyptic number.

It is an amenable number.

1868138369 is a deficient number, since it is larger than the sum of its proper divisors (306991).

1868138369 is an equidigital number, since it uses as much as digits as its factorization.

1868138369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306990.

The product of its digits is 1492992, while the sum is 53.

The square root of 1868138369 is about 43221.9662787338. The cubic root of 1868138369 is about 1231.5999996712.

The spelling of 1868138369 in words is "one billion, eight hundred sixty-eight million, one hundred thirty-eight thousand, three hundred sixty-nine".