1213745009 has 4 divisors (see below), whose sum is σ = 1218823680. Its totient is φ = 1208666340.

The previous prime is 1213744993. The next prime is 1213745011. The reversal of 1213745009 is 9005473121.

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: 9005473121 = 17 ⋅529733713.

It is a cyclic number.

It is not a de Polignac number, because 1213745009 - 2⁴ = 1213744993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213745059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2538977 + ... + 2539454.

It is an arithmetic number, because the mean of its divisors is an integer number (304705920).

Almost surely, 2^1213745009 is an apocalyptic number.

It is an amenable number.

1213745009 is a deficient number, since it is larger than the sum of its proper divisors (5078671).

1213745009 is an equidigital number, since it uses as much as digits as its factorization.

1213745009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5078670.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 1213745009 is about 34838.8433935457. The cubic root of 1213745009 is about 1066.7004681454.

The spelling of 1213745009 in words is "one billion, two hundred thirteen million, seven hundred forty-five thousand, nine".