18090943634 has 4 divisors (see below), whose sum is σ = 27136415454. Its totient is φ = 9045471816.

The previous prime is 18090943529. The next prime is 18090943639. The reversal of 18090943634 is 43634909081.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18089443009 + 1500625 = 134497^2 + 1225^2 .

It is not an unprimeable number, because it can be changed into a prime (18090943639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4522735907 + ... + 4522735910.

Almost surely, 2^18090943634 is an apocalyptic number.

18090943634 is a deficient number, since it is larger than the sum of its proper divisors (9045471820).

18090943634 is an equidigital number, since it uses as much as digits as its factorization.

18090943634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9045471819.

The product of its (nonzero) digits is 559872, while the sum is 47.

The spelling of 18090943634 in words is "eighteen billion, ninety million, nine hundred forty-three thousand, six hundred thirty-four".