181378073 has 4 divisors (see below), whose sum is σ = 181405620. Its totient is φ = 181350528.

The previous prime is 181378061. The next prime is 181378079. The reversal of 181378073 is 370873181.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 101042704 + 80335369 = 10052^2 + 8963^2 .

It is a cyclic number.

It is not a de Polignac number, because 181378073 - 2¹² = 181373977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181378079) 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, 2561 + ... + 19217.

It is an arithmetic number, because the mean of its divisors is an integer number (45351405).

Almost surely, 2^181378073 is an apocalyptic number.

It is an amenable number.

181378073 is a deficient number, since it is larger than the sum of its proper divisors (27547).

181378073 is a wasteful number, since it uses less digits than its factorization.

181378073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27546.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 181378073 is about 13467.6676896930. The cubic root of 181378073 is about 566.0588627616.

The spelling of 181378073 in words is "one hundred eighty-one million, three hundred seventy-eight thousand, seventy-three".