161646504251603 has 8 divisors (see below), whose sum is σ = 184742914812672. Its totient is φ = 138551106893256.

The previous prime is 161646504251527. The next prime is 161646504251611. The reversal of 161646504251603 is 306152405646161.

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

It is a cyclic number.

It is not a de Polignac number, because 161646504251603 - 2¹² = 161646504247507 is a prime.

It is a super-2 number, since 2×161646504251603² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161646504251633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 252958775 + ... + 253596992.

It is an arithmetic number, because the mean of its divisors is an integer number (23092864351584).

Almost surely, 2^{161646504251603} is an apocalyptic number.

161646504251603 is a deficient number, since it is larger than the sum of its proper divisors (23096410561069).

161646504251603 is an equidigital number, since it uses as much as digits as its factorization.

161646504251603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506601361.

The product of its (nonzero) digits is 3110400, while the sum is 50.

Adding to 161646504251603 its reverse (306152405646161), we get a palindrome (467798909897764).

The spelling of 161646504251603 in words is "one hundred sixty-one trillion, six hundred forty-six billion, five hundred four million, two hundred fifty-one thousand, six hundred three".