1243654213 has 4 divisors (see below), whose sum is σ = 1272576448. Its totient is φ = 1214731980.

The previous prime is 1243654151. The next prime is 1243654219. The reversal of 1243654213 is 3124563421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3124563421 = 7 ⋅446366203.

It is a cyclic number.

It is not a de Polignac number, because 1243654213 - 2²¹ = 1241557061 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 (1243654219) 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, 14461053 + ... + 14461138.

It is an arithmetic number, because the mean of its divisors is an integer number (318144112).

Almost surely, 2^1243654213 is an apocalyptic number.

It is an amenable number.

1243654213 is a deficient number, since it is larger than the sum of its proper divisors (28922235).

1243654213 is an equidigital number, since it uses as much as digits as its factorization.

1243654213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28922234.

The product of its digits is 17280, while the sum is 31.

The square root of 1243654213 is about 35265.4818909369. The cubic root of 1243654213 is about 1075.3913737749.

The spelling of 1243654213 in words is "one billion, two hundred forty-three million, six hundred fifty-four thousand, two hundred thirteen".