161655451 has 4 divisors (see below), whose sum is σ = 162361600. Its totient is φ = 160949304.

The previous prime is 161655443. The next prime is 161655463. The reversal of 161655451 is 154556161.

161655451 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: 154556161 = 607 ⋅254623.

It is a cyclic number.

It is not a de Polignac number, because 161655451 - 2³ = 161655443 is a prime.

It is a super-2 number, since 2×161655451² = 52264969676026802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161658451) 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, 352731 + ... + 353188.

It is an arithmetic number, because the mean of its divisors is an integer number (40590400).

Almost surely, 2^161655451 is an apocalyptic number.

161655451 is a deficient number, since it is larger than the sum of its proper divisors (706149).

161655451 is an equidigital number, since it uses as much as digits as its factorization.

161655451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706148.

The product of its digits is 18000, while the sum is 34.

The square root of 161655451 is about 12714.3796938742. The cubic root of 161655451 is about 544.7494300275.

The spelling of 161655451 in words is "one hundred sixty-one million, six hundred fifty-five thousand, four hundred fifty-one".