181456404529 has 3 divisors (see below), whose sum is σ = 181456830507. Its totient is φ = 181455978552.

The previous prime is 181456404491. The next prime is 181456404557. The reversal of 181456404529 is 925404654181.

The square root of 181456404529 is 425977.

It is a perfect power (a square), and thus also a powerful number.

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 only one way, i.e., 21298225 + 181435106304 = 4615^2 + 425952^2 .

It is not a de Polignac number, because 181456404529 - 2¹¹ = 181456402481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181456404029) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 212989 + ... + 638965.

It is an arithmetic number, because the mean of its divisors is an integer number (60485610169).

Almost surely, 2^181456404529 is an apocalyptic number.

181456404529 is the 425977-th square number.

181456404529 is the 212989-th centered octagonal number.

It is an amenable number.

181456404529 is a deficient number, since it is larger than the sum of its proper divisors (425978).

181456404529 is an frugal number, since it uses more digits than its factorization.

181456404529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851954 (or 425977 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 49.

Multiplying 181456404529 by its sum of digits (49), we get a square (8891363821921 = 2981839²).

The spelling of 181456404529 in words is "one hundred eighty-one billion, four hundred fifty-six million, four hundred four thousand, five hundred twenty-nine".