161841721678207 has 4 divisors (see below), whose sum is σ = 167062422377536. Its totient is φ = 156621020978880.

The previous prime is 161841721678201. The next prime is 161841721678277. The reversal of 161841721678207 is 702876127148161.

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

It is a cyclic number.

It is not a de Polignac number, because 161841721678207 - 2³¹ = 161839574194559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161841721678201) 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, 2610350349618 + ... + 2610350349679.

It is an arithmetic number, because the mean of its divisors is an integer number (41765605594384).

Almost surely, 2^{161841721678207} is an apocalyptic number.

161841721678207 is a deficient number, since it is larger than the sum of its proper divisors (5220700699329).

161841721678207 is an equidigital number, since it uses as much as digits as its factorization.

161841721678207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5220700699328.

The product of its (nonzero) digits is 12644352, while the sum is 61.

The spelling of 161841721678207 in words is "one hundred sixty-one trillion, eight hundred forty-one billion, seven hundred twenty-one million, six hundred seventy-eight thousand, two hundred seven".