181821534 has 8 divisors (see below), whose sum is σ = 363643080. Its totient is φ = 60607176.

The previous prime is 181821533. The next prime is 181821547. The reversal of 181821534 is 435128181.

181821534 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

181821534 is an admirable number.

It is a super-2 number, since 2×181821534² = 66118140452226312, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 181821495 and 181821504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181821533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15151789 + ... + 15151800.

It is an arithmetic number, because the mean of its divisors is an integer number (45455385).

Almost surely, 2^181821534 is an apocalyptic number.

181821534 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

181821534 is a wasteful number, since it uses less digits than its factorization.

181821534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30303594.

The product of its digits is 7680, while the sum is 33.

The square root of 181821534 is about 13484.1215509205. The cubic root of 181821534 is about 566.5198165419.

The spelling of 181821534 in words is "one hundred eighty-one million, eight hundred twenty-one thousand, five hundred thirty-four".