161921078133 has 8 divisors (see below), whose sum is σ = 227257653600. Its totient is φ = 102265944048.

The previous prime is 161921078131. The next prime is 161921078141. The reversal of 161921078133 is 331870129161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161921078133 - 2¹ = 161921078131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161921078131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1420360278 + ... + 1420360391.

It is an arithmetic number, because the mean of its divisors is an integer number (28407206700).

Almost surely, 2^161921078133 is an apocalyptic number.

It is an amenable number.

161921078133 is a deficient number, since it is larger than the sum of its proper divisors (65336575467).

161921078133 is a wasteful number, since it uses less digits than its factorization.

161921078133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2840720691.

The product of its (nonzero) digits is 54432, while the sum is 42.

The spelling of 161921078133 in words is "one hundred sixty-one billion, nine hundred twenty-one million, seventy-eight thousand, one hundred thirty-three".