18071693761 has 21 divisors (see below), whose sum is σ = 20077631251. Its totient is φ = 16266151000.

The previous prime is 18071693749. The next prime is 18071693789. The reversal of 18071693761 is 16739617081.

The square root of 18071693761 is 134431.

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

It can be written as a sum of positive squares in only one way, i.e., 17363069361 + 708624400 = 131769^2 + 26620^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18071693761 is a prime.

It is a super-2 number, since 2×18071693761² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18071693161) 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 20 ways as a sum of consecutive naturals, for example, 178927611 + ... + 178927711.

Almost surely, 2^18071693761 is an apocalyptic number.

18071693761 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18071693761 is the 134431-st square number.

18071693761 is the 67216-th centered octagonal number.

It is an amenable number.

18071693761 is a deficient number, since it is larger than the sum of its proper divisors (2005937490).

18071693761 is an frugal number, since it uses more digits than its factorization.

18071693761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 49.

Multiplying 18071693761 by its sum of digits (49), we get a square (885512994289 = 941017²).

The spelling of 18071693761 in words is "eighteen billion, seventy-one million, six hundred ninety-three thousand, seven hundred sixty-one".