18809437690 has 16 divisors (see below), whose sum is σ = 34320783528. Its totient is φ = 7420709376.

The previous prime is 18809437681. The next prime is 18809437723. The reversal of 18809437690 is 9673490881.

It can be written as a sum of positive squares in 4 ways, for example, as 18195042321 + 614395369 = 134889^2 + 24787^2 .

It is a super-2 number, since 2×18809437690² (a number of 21 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 12882447 + ... + 12883906.

Almost surely, 2^18809437690 is an apocalyptic number.

18809437690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18809437690 is a deficient number, since it is larger than the sum of its proper divisors (15511345838).

18809437690 is a wasteful number, since it uses less digits than its factorization.

18809437690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25766433.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The spelling of 18809437690 in words is "eighteen billion, eight hundred nine million, four hundred thirty-seven thousand, six hundred ninety".