181916145 has 16 divisors (see below), whose sum is σ = 323406720. Its totient is φ = 97021872.

The previous prime is 181916143. The next prime is 181916183. The reversal of 181916145 is 541619181.

It is a happy number.

It is not a de Polignac number, because 181916145 - 2¹ = 181916143 is a prime.

It is a super-2 number, since 2×181916145² = 66186967623322050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (181916143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 673629 + ... + 673898.

It is an arithmetic number, because the mean of its divisors is an integer number (20212920).

Almost surely, 2^181916145 is an apocalyptic number.

181916145 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181916145 is a deficient number, since it is larger than the sum of its proper divisors (141490575).

181916145 is a wasteful number, since it uses less digits than its factorization.

181916145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347541 (or 1347535 counting only the distinct ones).

The product of its digits is 8640, while the sum is 36.

The square root of 181916145 is about 13487.6293320954. The cubic root of 181916145 is about 566.6180625364.

It can be divided in two parts, 18191 and 6145, that added together give a square (24336 = 156²).

The spelling of 181916145 in words is "one hundred eighty-one million, nine hundred sixteen thousand, one hundred forty-five".