1245511213 has 4 divisors (see below), whose sum is σ = 1248617628. Its totient is φ = 1242404800.

The previous prime is 1245511187. The next prime is 1245511219. The reversal of 1245511213 is 3121155421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3121155421 = 29 ⋅107626049.

It can be written as a sum of positive squares in 2 ways, for example, as 1239251209 + 6260004 = 35203^2 + 2502^2 .

It is a cyclic number.

It is not a de Polignac number, because 1245511213 - 2¹⁷ = 1245380141 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 (1245511219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1552606 + ... + 1553407.

It is an arithmetic number, because the mean of its divisors is an integer number (312154407).

Almost surely, 2^1245511213 is an apocalyptic number.

It is an amenable number.

1245511213 is a deficient number, since it is larger than the sum of its proper divisors (3106415).

1245511213 is an equidigital number, since it uses as much as digits as its factorization.

1245511213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3106414.

The product of its digits is 1200, while the sum is 25.

The square root of 1245511213 is about 35291.8009316612. The cubic root of 1245511213 is about 1075.9263586666.

Adding to 1245511213 its reverse (3121155421), we get a palindrome (4366666634).

The spelling of 1245511213 in words is "one billion, two hundred forty-five million, five hundred eleven thousand, two hundred thirteen".