181401327297961 has 9 divisors (see below), whose sum is σ = 182221451023671. Its totient is φ = 180584878417272.

The previous prime is 181401327297919. The next prime is 181401327297973. The reversal of 181401327297961 is 169792723104181.

It is a happy number.

The square root of 181401327297961 is 13468531.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 40804435987225 + 140596891310736 = 6387835^2 + 11857356^2 .

It is not a de Polignac number, because 181401327297961 - 2²³ = 181401318909353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 181401327297961.

It is not an unprimeable number, because it can be changed into a prime (181401327297991) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3003452215 + ... + 3003512611.

It is an arithmetic number, because the mean of its divisors is an integer number (20246827891519).

Almost surely, 2^{181401327297961} is an apocalyptic number.

181401327297961 is the 13468531-st square number.

181401327297961 is the 6734266-th centered octagonal number.

It is an amenable number.

181401327297961 is a deficient number, since it is larger than the sum of its proper divisors (820123725710).

181401327297961 is an frugal number, since it uses more digits than its factorization.

181401327297961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121240 (or 60620 counting only the distinct ones).

The product of its (nonzero) digits is 9144576, while the sum is 61.

The spelling of 181401327297961 in words is "one hundred eighty-one trillion, four hundred one billion, three hundred twenty-seven million, two hundred ninety-seven thousand, nine hundred sixty-one".