1218628281731 has 8 divisors (see below), whose sum is σ = 1397674330464. Its totient is φ = 1040821306560.

The previous prime is 1218628281721. The next prime is 1218628281737. The reversal of 1218628281731 is 1371828268121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1218628281731 - 2¹⁴ = 1218628265347 is a prime.

It is a super-2 number, since 2×1218628281731² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1218628281731.

It is not an unprimeable number, because it can be changed into a prime (1218628281737) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309766280 + ... + 309770213.

It is an arithmetic number, because the mean of its divisors is an integer number (174709291308).

Almost surely, 2^{1218628281731} is an apocalyptic number.

1218628281731 is a deficient number, since it is larger than the sum of its proper divisors (179046048733).

1218628281731 is an equidigital number, since it uses as much as digits as its factorization.

1218628281731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619536781.

The product of its digits is 516096, while the sum is 50.

The spelling of 1218628281731 in words is "one trillion, two hundred eighteen billion, six hundred twenty-eight million, two hundred eighty-one thousand, seven hundred thirty-one".