1223515138 has 4 divisors (see below), whose sum is σ = 1835272710. Its totient is φ = 611757568.

The previous prime is 1223515121. The next prime is 1223515141. The reversal of 1223515138 is 8315153221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1223390529 + 124609 = 34977^2 + 353^2 .

It is an unprimeable number.

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, 305878783 + ... + 305878786.

Almost surely, 2^1223515138 is an apocalyptic number.

1223515138 is a deficient number, since it is larger than the sum of its proper divisors (611757572).

1223515138 is an equidigital number, since it uses as much as digits as its factorization.

1223515138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611757571.

The product of its digits is 7200, while the sum is 31.

The square root of 1223515138 is about 34978.7812537830. The cubic root of 1223515138 is about 1069.5549836612.

Adding to 1223515138 its reverse (8315153221), we get a palindrome (9538668359).

The spelling of 1223515138 in words is "one billion, two hundred twenty-three million, five hundred fifteen thousand, one hundred thirty-eight".