181520784442 has 4 divisors (see below), whose sum is σ = 272281176666. Its totient is φ = 90760392220.

The previous prime is 181520784371. The next prime is 181520784461. The reversal of 181520784442 is 244487025181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 126507551041 + 55013233401 = 355679^2 + 234549^2 .

It is a junction number, because it is equal to n+sod(n) for n = 181520784392 and 181520784401.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45380196109 + ... + 45380196112.

Almost surely, 2^181520784442 is an apocalyptic number.

181520784442 is a deficient number, since it is larger than the sum of its proper divisors (90760392224).

181520784442 is an equidigital number, since it uses as much as digits as its factorization.

181520784442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90760392223.

The product of its (nonzero) digits is 573440, while the sum is 46.

The spelling of 181520784442 in words is "one hundred eighty-one billion, five hundred twenty million, seven hundred eighty-four thousand, four hundred forty-two".