1218574109 has 4 divisors (see below), whose sum is σ = 1271555616. Its totient is φ = 1165592604.

The previous prime is 1218574103. The next prime is 1218574121. The reversal of 1218574109 is 9014758121.

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: 9014758121 = 251 ⋅35915371.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1218574109 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 (1218574103) 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, 26490719 + ... + 26490764.

It is an arithmetic number, because the mean of its divisors is an integer number (317888904).

Almost surely, 2^1218574109 is an apocalyptic number.

It is an amenable number.

1218574109 is a deficient number, since it is larger than the sum of its proper divisors (52981507).

1218574109 is an equidigital number, since it uses as much as digits as its factorization.

1218574109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52981506.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 1218574109 is about 34908.0808552977. The cubic root of 1218574109 is about 1068.1132818184.

The spelling of 1218574109 in words is "one billion, two hundred eighteen million, five hundred seventy-four thousand, one hundred nine".