181997601 has 16 divisors (see below), whose sum is σ = 249664896. Its totient is φ = 117876096.

The previous prime is 181997581. The next prime is 181997609. The reversal of 181997601 is 106799181.

It is not a de Polignac number, because 181997601 - 2⁹ = 181997089 is a prime.

It is a tribonacci number.

It is not an unprimeable number, because it can be changed into a prime (181997609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10821 + ... + 21933.

It is an arithmetic number, because the mean of its divisors is an integer number (15604056).

Almost surely, 2^181997601 is an apocalyptic number.

It is an amenable number.

181997601 is a deficient number, since it is larger than the sum of its proper divisors (67667295).

181997601 is a wasteful number, since it uses less digits than its factorization.

181997601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11272.

The product of its (nonzero) digits is 27216, while the sum is 42.

The square root of 181997601 is about 13490.6486500835. The cubic root of 181997601 is about 566.7026208252.

The spelling of 181997601 in words is "one hundred eighty-one million, nine hundred ninety-seven thousand, six hundred one".