18894943636 has 6 divisors (see below), whose sum is σ = 33066151370. Its totient is φ = 9447471816.

The previous prime is 18894943633. The next prime is 18894943667. The reversal of 18894943636 is 63634949881.

It can be written as a sum of positive squares in only one way, i.e., 14186239236 + 4708704400 = 119106^2 + 68620^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18894943631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2361867951 + ... + 2361867958.

Almost surely, 2^18894943636 is an apocalyptic number.

It is an amenable number.

18894943636 is a deficient number, since it is larger than the sum of its proper divisors (14171207734).

18894943636 is a wasteful number, since it uses less digits than its factorization.

18894943636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4723735913 (or 4723735911 counting only the distinct ones).

The product of its digits is 26873856, while the sum is 61.

The spelling of 18894943636 in words is "eighteen billion, eight hundred ninety-four million, nine hundred forty-three thousand, six hundred thirty-six".