1243214521 has 2 divisors, whose sum is σ = 1243214522. Its totient is φ = 1243214520.

The previous prime is 1243214509. The next prime is 1243214537. The reversal of 1243214521 is 1254123421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1062042921 + 181171600 = 32589^2 + 13460^2 .

It is an emirp because it is prime and its reverse (1254123421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1243214521 - 2¹³ = 1243206329 is a prime.

It is not a weakly prime, because it can be changed into another prime (1243214551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621607260 + 621607261.

It is an arithmetic number, because the mean of its divisors is an integer number (621607261).

Almost surely, 2^1243214521 is an apocalyptic number.

It is an amenable number.

1243214521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243214521 is an equidigital number, since it uses as much as digits as its factorization.

1243214521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 25.

The square root of 1243214521 is about 35259.2473118755. The cubic root of 1243214521 is about 1075.2646245242.

Adding to 1243214521 its reverse (1254123421), we get a palindrome (2497337942).

The spelling of 1243214521 in words is "one billion, two hundred forty-three million, two hundred fourteen thousand, five hundred twenty-one".