161651841 has 8 divisors (see below), whose sum is σ = 232115520. Its totient is φ = 99478032.

The previous prime is 161651839. The next prime is 161651869. The reversal of 161651841 is 148156161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161651841 - 2¹ = 161651839 is a prime.

It is a super-2 number, since 2×161651841² = 52262635397378562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161651801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2072421 + ... + 2072498.

It is an arithmetic number, because the mean of its divisors is an integer number (29014440).

Almost surely, 2^161651841 is an apocalyptic number.

It is an amenable number.

161651841 is a deficient number, since it is larger than the sum of its proper divisors (70463679).

161651841 is a wasteful number, since it uses less digits than its factorization.

161651841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4144935.

The product of its digits is 5760, while the sum is 33.

The square root of 161651841 is about 12714.2377278388. The cubic root of 161651841 is about 544.7453749831.

The spelling of 161651841 in words is "one hundred sixty-one million, six hundred fifty-one thousand, eight hundred forty-one".