181620242 has 16 divisors (see below), whose sum is σ = 279791064. Its totient is φ = 88368000.

The previous prime is 181620223. The next prime is 181620281. The reversal of 181620242 is 242026181.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 69239041 + 112381201 = 8321^2 + 10601^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31892 + ... + 37152.

Almost surely, 2^181620242 is an apocalyptic number.

181620242 is a deficient number, since it is larger than the sum of its proper divisors (98170822).

181620242 is a wasteful number, since it uses less digits than its factorization.

181620242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5725.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 181620242 is about 13476.6554456215. The cubic root of 181620242 is about 566.3106773697.

The spelling of 181620242 in words is "one hundred eighty-one million, six hundred twenty thousand, two hundred forty-two".