123315521 has 8 divisors (see below), whose sum is σ = 141671424. Its totient is φ = 105144480.

The previous prime is 123315503. The next prime is 123315527. The reversal of 123315521 is 125513321.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-123315521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123315527) 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 7 ways as a sum of consecutive naturals, for example, 44780 + ... + 47453.

It is an arithmetic number, because the mean of its divisors is an integer number (17708928).

Almost surely, 2^123315521 is an apocalyptic number.

It is an amenable number.

123315521 is a deficient number, since it is larger than the sum of its proper divisors (18355903).

123315521 is an equidigital number, since it uses as much as digits as its factorization.

123315521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92431.

The product of its digits is 900, while the sum is 23.

The square root of 123315521 is about 11104.7521809359. The cubic root of 123315521 is about 497.7438630038.

Adding to 123315521 its reverse (125513321), we get a palindrome (248828842).

The spelling of 123315521 in words is "one hundred twenty-three million, three hundred fifteen thousand, five hundred twenty-one".