1213023505 has 4 divisors (see below), whose sum is σ = 1455628212. Its totient is φ = 970418800.

The previous prime is 1213023463. The next prime is 1213023527. The reversal of 1213023505 is 5053203121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5053203121 = 19 ⋅265958059.

It can be written as a sum of positive squares in 2 ways, for example, as 955613569 + 257409936 = 30913^2 + 16044^2 .

It is not a de Polignac number, because 1213023505 - 2⁷ = 1213023377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121302346 + ... + 121302355.

It is an arithmetic number, because the mean of its divisors is an integer number (363907053).

Almost surely, 2^1213023505 is an apocalyptic number.

It is an amenable number.

1213023505 is a deficient number, since it is larger than the sum of its proper divisors (242604707).

1213023505 is an equidigital number, since it uses as much as digits as its factorization.

1213023505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242604706.

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 1213023505 is about 34828.4869754631. The cubic root of 1213023505 is about 1066.4890615211.

Adding to 1213023505 its reverse (5053203121), we get a palindrome (6266226626).

The spelling of 1213023505 in words is "one billion, two hundred thirteen million, twenty-three thousand, five hundred five".