181493996437 has 36 divisors (see below), whose sum is σ = 201238122540. Its totient is φ = 163680528960.

The previous prime is 181493996423. The next prime is 181493996501. The reversal of 181493996437 is 734699394181.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 18 ways, for example, as 19894820401 + 161599176036 = 141049^2 + 401994^2 .

It is a de Polignac number, because none of the positive numbers 2^k-181493996437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181493996737) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1218080439 + ... + 1218080587.

Almost surely, 2^181493996437 is an apocalyptic number.

It is an amenable number.

181493996437 is a deficient number, since it is larger than the sum of its proper divisors (19744126103).

181493996437 is an frugal number, since it uses more digits than its factorization.

181493996437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459 (or 223 counting only the distinct ones).

The product of its digits is 35271936, while the sum is 64.

The spelling of 181493996437 in words is "one hundred eighty-one billion, four hundred ninety-three million, nine hundred ninety-six thousand, four hundred thirty-seven".