18891609424 has 10 divisors (see below), whose sum is σ = 36602493290. Its totient is φ = 9445804704.

The previous prime is 18891609421. The next prime is 18891609437. The reversal of 18891609424 is 42490619881.

It can be written as a sum of positive squares in only one way, i.e., 18732849424 + 158760000 = 136868^2 + 12600^2 .

It is a super-2 number, since 2×18891609424² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18891609421) 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 as a sum of consecutive naturals, namely, 590362779 + ... + 590362810.

It is an arithmetic number, because the mean of its divisors is an integer number (3660249329).

Almost surely, 2^18891609424 is an apocalyptic number.

It is an amenable number.

18891609424 is a deficient number, since it is larger than the sum of its proper divisors (17710883866).

18891609424 is a wasteful number, since it uses less digits than its factorization.

18891609424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180725597 (or 1180725591 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 52.

The spelling of 18891609424 in words is "eighteen billion, eight hundred ninety-one million, six hundred nine thousand, four hundred twenty-four".