18201605799556 has 9 divisors (see below), whose sum is σ = 31852825081399. Its totient is φ = 9100798633444.

The previous prime is 18201605799493. The next prime is 18201605799563. The reversal of 18201605799556 is 65599750610281.

The square root of 18201605799556 is 4266334.

It is a perfect power (a square), and thus also a powerful number.

It is a super-2 number, since 2×18201605799556² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7466085 + ... + 9599251.

Almost surely, 2^{18201605799556} is an apocalyptic number.

18201605799556 is the 4266334-th square number.

It is an amenable number.

18201605799556 is a deficient number, since it is larger than the sum of its proper divisors (13651219281843).

18201605799556 is an frugal number, since it uses more digits than its factorization.

18201605799556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4266338 (or 2133169 counting only the distinct ones).

The product of its (nonzero) digits is 40824000, while the sum is 64.

The spelling of 18201605799556 in words is "eighteen trillion, two hundred one billion, six hundred five million, seven hundred ninety-nine thousand, five hundred fifty-six".