161973377 has 4 divisors (see below), whose sum is σ = 162036996. Its totient is φ = 161909760.

The previous prime is 161973359. The next prime is 161973379. The reversal of 161973377 is 773379161.

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

It can be written as a sum of positive squares in 2 ways, for example, as 37405456 + 124567921 = 6116^2 + 11161^2 .

It is a cyclic number.

It is not a de Polignac number, because 161973377 - 2⁶ = 161973313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161973379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27824 + ... + 33137.

It is an arithmetic number, because the mean of its divisors is an integer number (40509249).

Almost surely, 2^161973377 is an apocalyptic number.

It is an amenable number.

161973377 is a deficient number, since it is larger than the sum of its proper divisors (63619).

161973377 is an equidigital number, since it uses as much as digits as its factorization.

161973377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63618.

The product of its digits is 166698, while the sum is 44.

The square root of 161973377 is about 12726.8761681726. The cubic root of 161973377 is about 545.1063137435.

The spelling of 161973377 in words is "one hundred sixty-one million, nine hundred seventy-three thousand, three hundred seventy-seven".