123215506 has 4 divisors (see below), whose sum is σ = 184823262. Its totient is φ = 61607752.

The previous prime is 123215489. The next prime is 123215509. The reversal of 123215506 is 605512321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 605512321 = 719 ⋅842159.

It can be written as a sum of positive squares in only one way, i.e., 117527281 + 5688225 = 10841^2 + 2385^2 .

It is not an unprimeable number, because it can be changed into a prime (123215509) 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 as a sum of consecutive naturals, namely, 30803875 + ... + 30803878.

Almost surely, 2^123215506 is an apocalyptic number.

123215506 is a deficient number, since it is larger than the sum of its proper divisors (61607756).

123215506 is an equidigital number, since it uses as much as digits as its factorization.

123215506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61607755.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 123215506 is about 11100.2480152472. The cubic root of 123215506 is about 497.6092616262.

Adding to 123215506 its reverse (605512321), we get a palindrome (728727827).

The spelling of 123215506 in words is "one hundred twenty-three million, two hundred fifteen thousand, five hundred six".