181207901953 has 4 divisors (see below), whose sum is σ = 195146971348. Its totient is φ = 167268832560.

The previous prime is 181207901929. The next prime is 181207901989. The reversal of 181207901953 is 359109702181.

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

It can be written as a sum of positive squares in 2 ways, for example, as 59021301249 + 122186600704 = 242943^2 + 349552^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181207901953 is a prime.

It is a super-2 number, since 2×181207901953² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181207901993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6969534678 + ... + 6969534703.

It is an arithmetic number, because the mean of its divisors is an integer number (48786742837).

Almost surely, 2^181207901953 is an apocalyptic number.

181207901953 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

181207901953 is a deficient number, since it is larger than the sum of its proper divisors (13939069395).

181207901953 is a wasteful number, since it uses less digits than its factorization.

181207901953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13939069394.

The product of its (nonzero) digits is 136080, while the sum is 46.

The spelling of 181207901953 in words is "one hundred eighty-one billion, two hundred seven million, nine hundred one thousand, nine hundred fifty-three".