161254551 has 4 divisors (see below), whose sum is σ = 215006072. Its totient is φ = 107503032.

The previous prime is 161254523. The next prime is 161254553. The reversal of 161254551 is 155452161.

161254551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155452161 = 3 ⋅51817387.

It is not a de Polignac number, because 161254551 - 2⁵ = 161254519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161254553) 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, 26875756 + ... + 26875761.

It is an arithmetic number, because the mean of its divisors is an integer number (53751518).

Almost surely, 2^161254551 is an apocalyptic number.

161254551 is a deficient number, since it is larger than the sum of its proper divisors (53751521).

161254551 is an equidigital number, since it uses as much as digits as its factorization.

161254551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53751520.

The product of its digits is 6000, while the sum is 30.

The square root of 161254551 is about 12698.6042933859. The cubic root of 161254551 is about 544.2987372576.

The spelling of 161254551 in words is "one hundred sixty-one million, two hundred fifty-four thousand, five hundred fifty-one".