161758243 has 4 divisors (see below), whose sum is σ = 165703608. Its totient is φ = 157812880.

The previous prime is 161758237. The next prime is 161758277. The reversal of 161758243 is 342857161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 342857161 = 12329 ⋅27809.

It is a cyclic number.

It is not a de Polignac number, because 161758243 - 2⁹ = 161757731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161758643) 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, 1972621 + ... + 1972702.

It is an arithmetic number, because the mean of its divisors is an integer number (41425902).

Almost surely, 2^161758243 is an apocalyptic number.

161758243 is a deficient number, since it is larger than the sum of its proper divisors (3945365).

161758243 is an equidigital number, since it uses as much as digits as its factorization.

161758243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3945364.

The product of its digits is 40320, while the sum is 37.

The square root of 161758243 is about 12718.4214036177. The cubic root of 161758243 is about 544.8648690029.

The spelling of 161758243 in words is "one hundred sixty-one million, seven hundred fifty-eight thousand, two hundred forty-three".