161556247 has 4 divisors (see below), whose sum is σ = 162393520. Its totient is φ = 160718976.

The previous prime is 161556233. The next prime is 161556251. The reversal of 161556247 is 742655161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 742655161 = 10391 ⋅71471.

It is a cyclic number.

It is not a de Polignac number, because 161556247 - 2²³ = 153167639 is a prime.

It is a super-2 number, since 2×161556247² = 52200841889450018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161556257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 418347 + ... + 418732.

It is an arithmetic number, because the mean of its divisors is an integer number (40598380).

Almost surely, 2^161556247 is an apocalyptic number.

161556247 is a deficient number, since it is larger than the sum of its proper divisors (837273).

161556247 is an equidigital number, since it uses as much as digits as its factorization.

161556247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837272.

The product of its digits is 50400, while the sum is 37.

The square root of 161556247 is about 12710.4778431025. The cubic root of 161556247 is about 544.6379740873.

The spelling of 161556247 in words is "one hundred sixty-one million, five hundred fifty-six thousand, two hundred forty-seven".