1213214645 has 18 divisors (see below), whose sum is σ = 1499831046. Its totient is φ = 942096960.

The previous prime is 1213214633. The next prime is 1213214647. The reversal of 1213214645 is 5464123121.

It can be written as a sum of positive squares in 9 ways, for example, as 533517604 + 679697041 = 23098^2 + 26071^2 .

It is not a de Polignac number, because 1213214645 - 2⁸ = 1213214389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213214647) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2881535 + ... + 2881955.

It is an arithmetic number, because the mean of its divisors is an integer number (83323947).

Almost surely, 2^1213214645 is an apocalyptic number.

It is an amenable number.

1213214645 is a deficient number, since it is larger than the sum of its proper divisors (286616401).

1213214645 is an frugal number, since it uses more digits than its factorization.

1213214645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921 (or 463 counting only the distinct ones).

The product of its digits is 5760, while the sum is 29.

The square root of 1213214645 is about 34831.2308855142. The cubic root of 1213214645 is about 1066.5450752785.

Adding to 1213214645 its reverse (5464123121), we get a palindrome (6677337766).

The spelling of 1213214645 in words is "one billion, two hundred thirteen million, two hundred fourteen thousand, six hundred forty-five".