161006501 has 4 divisors (see below), whose sum is σ = 161246412. Its totient is φ = 160766592.

The previous prime is 161006497. The next prime is 161006533. The reversal of 161006501 is 105600161.

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: 105600161 = 2053 ⋅51437.

It can be written as a sum of positive squares in 2 ways, for example, as 63984001 + 97022500 = 7999^2 + 9850^2 .

It is a cyclic number.

It is not a de Polignac number, because 161006501 - 2² = 161006497 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 (161006701) 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, 118946 + ... + 120291.

It is an arithmetic number, because the mean of its divisors is an integer number (40311603).

Almost surely, 2^161006501 is an apocalyptic number.

It is an amenable number.

161006501 is a deficient number, since it is larger than the sum of its proper divisors (239911).

161006501 is an equidigital number, since it uses as much as digits as its factorization.

161006501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239910.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 161006501 is about 12688.8337131511. The cubic root of 161006501 is about 544.0195046442.

Adding to 161006501 its reverse (105600161), we get a palindrome (266606662).

The spelling of 161006501 in words is "one hundred sixty-one million, six thousand, five hundred one".