171812012951561 has 4 divisors (see below), whose sum is σ = 171812142732672. Its totient is φ = 171811883170452.

The previous prime is 171812012951521. The next prime is 171812012951563. The reversal of 171812012951561 is 165159210218171.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 171812012951561 - 2³⁸ = 171537135044617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (171812012951563) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 62884085 + ... + 65559378.

It is an arithmetic number, because the mean of its divisors is an integer number (42953035683168).

Almost surely, 2^{171812012951561} is an apocalyptic number.

It is an amenable number.

171812012951561 is a deficient number, since it is larger than the sum of its proper divisors (129781111).

171812012951561 is a wasteful number, since it uses less digits than its factorization.

171812012951561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129781110.

The product of its (nonzero) digits is 302400, while the sum is 50.

The spelling of 171812012951561 in words is "one hundred seventy-one trillion, eight hundred twelve billion, twelve million, nine hundred fifty-one thousand, five hundred sixty-one".