161217451 has 4 divisors (see below), whose sum is σ = 169702600. Its totient is φ = 152732304.

The previous prime is 161217401. The next prime is 161217487. The reversal of 161217451 is 154712161.

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

It is a cyclic number.

It is not a de Polignac number, because 161217451 - 2¹⁷ = 161086379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161217401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4242546 + ... + 4242583.

It is an arithmetic number, because the mean of its divisors is an integer number (42425650).

Almost surely, 2^161217451 is an apocalyptic number.

161217451 is a deficient number, since it is larger than the sum of its proper divisors (8485149).

161217451 is an equidigital number, since it uses as much as digits as its factorization.

161217451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8485148.

The product of its digits is 1680, while the sum is 28.

The square root of 161217451 is about 12697.1434188954. The cubic root of 161217451 is about 544.2569915997.

The spelling of 161217451 in words is "one hundred sixty-one million, two hundred seventeen thousand, four hundred fifty-one".