1816539636 has 24 divisors (see below), whose sum is σ = 4276105344. Its totient is φ = 600154240.

The previous prime is 1816539623. The next prime is 1816539691. The reversal of 1816539636 is 6369356181.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 668460 + ... + 671171.

It is an arithmetic number, because the mean of its divisors is an integer number (178171056).

Almost surely, 2^1816539636 is an apocalyptic number.

It is an amenable number.

1816539636 is an abundant number, since it is smaller than the sum of its proper divisors (2459565708).

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

1816539636 is a wasteful number, since it uses less digits than its factorization.

1816539636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339751 (or 1339749 counting only the distinct ones).

The product of its digits is 699840, while the sum is 48.

The square root of 1816539636 is about 42620.8826281202. The cubic root of 1816539636 is about 1220.1548750798.

The spelling of 1816539636 in words is "one billion, eight hundred sixteen million, five hundred thirty-nine thousand, six hundred thirty-six".