161798649 has 4 divisors (see below), whose sum is σ = 215731536. Its totient is φ = 107865764.

The previous prime is 161798647. The next prime is 161798671. The reversal of 161798649 is 946897161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161798649 - 2¹ = 161798647 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161798647) 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, 26966439 + ... + 26966444.

It is an arithmetic number, because the mean of its divisors is an integer number (53932884).

Almost surely, 2^161798649 is an apocalyptic number.

It is an amenable number.

161798649 is a deficient number, since it is larger than the sum of its proper divisors (53932887).

161798649 is an equidigital number, since it uses as much as digits as its factorization.

161798649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53932886.

The product of its digits is 653184, while the sum is 51.

The square root of 161798649 is about 12720.0097877321. The cubic root of 161798649 is about 544.9102329497.

The spelling of 161798649 in words is "one hundred sixty-one million, seven hundred ninety-eight thousand, six hundred forty-nine".