161215201523 has 4 divisors (see below), whose sum is σ = 161323183728. Its totient is φ = 161107219320.

The previous prime is 161215201513. The next prime is 161215201531. The reversal of 161215201523 is 325102512161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 325102512161 = 7 ⋅46443216023.

It is a cyclic number.

It is not a de Polignac number, because 161215201523 - 2¹² = 161215197427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161215201513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53988863 + ... + 53991848.

It is an arithmetic number, because the mean of its divisors is an integer number (40330795932).

Almost surely, 2^161215201523 is an apocalyptic number.

161215201523 is a deficient number, since it is larger than the sum of its proper divisors (107982205).

161215201523 is a wasteful number, since it uses less digits than its factorization.

161215201523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107982204.

The product of its (nonzero) digits is 3600, while the sum is 29.

Adding to 161215201523 its reverse (325102512161), we get a palindrome (486317713684).

The spelling of 161215201523 in words is "one hundred sixty-one billion, two hundred fifteen million, two hundred one thousand, five hundred twenty-three".