161216455 has 4 divisors (see below), whose sum is σ = 193459752. Its totient is φ = 128973160.

The previous prime is 161216441. The next prime is 161216479. The reversal of 161216455 is 554612161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 554612161 = 6269 ⋅88469.

It is not a de Polignac number, because 161216455 - 2¹¹ = 161214407 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 16121641 + ... + 16121650.

It is an arithmetic number, because the mean of its divisors is an integer number (48364938).

Almost surely, 2^161216455 is an apocalyptic number.

161216455 is a deficient number, since it is larger than the sum of its proper divisors (32243297).

161216455 is an equidigital number, since it uses as much as digits as its factorization.

161216455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32243296.

The product of its digits is 7200, while the sum is 31.

The square root of 161216455 is about 12697.1041974145. The cubic root of 161216455 is about 544.2558707924.

The spelling of 161216455 in words is "one hundred sixty-one million, two hundred sixteen thousand, four hundred fifty-five".