181997530 has 32 divisors (see below), whose sum is σ = 384870528. Its totient is φ = 61089600.

The previous prime is 181997507. The next prime is 181997539. The reversal of 181997530 is 35799181.

It is a super-2 number, since 2×181997530² = 66246201852201800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (181997539) 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, 62206 + ... + 65065.

It is an arithmetic number, because the mean of its divisors is an integer number (12027204).

Almost surely, 2^181997530 is an apocalyptic number.

181997530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

181997530 is an abundant number, since it is smaller than the sum of its proper divisors (202872998).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

181997530 is a wasteful number, since it uses less digits than its factorization.

181997530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127302.

The product of its (nonzero) digits is 68040, while the sum is 43.

The square root of 181997530 is about 13490.6460186308. The cubic root of 181997530 is about 566.7025471321.

The spelling of 181997530 in words is "one hundred eighty-one million, nine hundred ninety-seven thousand, five hundred thirty".