181212705 has 12 divisors (see below), whose sum is σ = 314102100. Its totient is φ = 96646752.

The previous prime is 181212679. The next prime is 181212727. The reversal of 181212705 is 507212181.

It can be written as a sum of positive squares in 2 ways, for example, as 21013056 + 160199649 = 4584^2 + 12657^2 .

It is not a de Polignac number, because 181212705 - 2⁶ = 181212641 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2013430 + ... + 2013519.

It is an arithmetic number, because the mean of its divisors is an integer number (26175175).

Almost surely, 2^181212705 is an apocalyptic number.

181212705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181212705 is a deficient number, since it is larger than the sum of its proper divisors (132889395).

181212705 is a wasteful number, since it uses less digits than its factorization.

181212705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4026960 (or 4026957 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 181212705 is about 13461.5268450499. The cubic root of 181212705 is about 565.8867793277.

Adding to 181212705 its reverse (507212181), we get a palindrome (688424886).

The spelling of 181212705 in words is "one hundred eighty-one million, two hundred twelve thousand, seven hundred five".