18361352561 has 8 divisors (see below), whose sum is σ = 18391401000. Its totient is φ = 18331331200.

The previous prime is 18361352543. The next prime is 18361352567. The reversal of 18361352561 is 16525316381.

It can be written as a sum of positive squares in 4 ways, for example, as 148230625 + 18213121936 = 12175^2 + 134956^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18361352561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18361352567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1671515 + ... + 1682463.

It is an arithmetic number, because the mean of its divisors is an integer number (2298925125).

Almost surely, 2^18361352561 is an apocalyptic number.

It is an amenable number.

18361352561 is a deficient number, since it is larger than the sum of its proper divisors (30048439).

18361352561 is a wasteful number, since it uses less digits than its factorization.

18361352561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13539.

The product of its digits is 129600, while the sum is 41.

The spelling of 18361352561 in words is "eighteen billion, three hundred sixty-one million, three hundred fifty-two thousand, five hundred sixty-one".