1819668636 has 36 divisors (see below), whose sum is σ = 4603419912. Its totient is φ = 606068064.

The previous prime is 1819668583. The next prime is 1819668647. The reversal of 1819668636 is 6368669181.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×1819668636² = 6622387889684200992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26490 + ... + 65886.

Almost surely, 2^1819668636 is an apocalyptic number.

It is an amenable number.

1819668636 is an abundant number, since it is smaller than the sum of its proper divisors (2783751276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1819668636 is a wasteful number, since it uses less digits than its factorization.

1819668636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40690 (or 40685 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 54.

The square root of 1819668636 is about 42657.5741926331. The cubic root of 1819668636 is about 1220.8550478196.

The spelling of 1819668636 in words is "one billion, eight hundred nineteen million, six hundred sixty-eight thousand, six hundred thirty-six".