161951973 has 8 divisors (see below), whose sum is σ = 216009888. Its totient is φ = 107931024.

The previous prime is 161951903. The next prime is 161951983. The reversal of 161951973 is 379159161.

161951973 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 161951973 - 2¹³ = 161943781 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161951903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3490 + ... + 18332.

It is an arithmetic number, because the mean of its divisors is an integer number (27001236).

Almost surely, 2^161951973 is an apocalyptic number.

It is an amenable number.

161951973 is a deficient number, since it is larger than the sum of its proper divisors (54057915).

161951973 is a wasteful number, since it uses less digits than its factorization.

161951973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18483.

The product of its digits is 51030, while the sum is 42.

The square root of 161951973 is about 12726.0352427612. The cubic root of 161951973 is about 545.0823016297.

The spelling of 161951973 in words is "one hundred sixty-one million, nine hundred fifty-one thousand, nine hundred seventy-three".