1218139607231 has 4 divisors (see below), whose sum is σ = 1231826569200. Its totient is φ = 1204452645264.

The previous prime is 1218139607203. The next prime is 1218139607261. The reversal of 1218139607231 is 1327069318121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1218139607231 - 2¹⁴ = 1218139590847 is a prime.

It is a super-2 number, since 2×1218139607231² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218139607261) 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, 6843480851 + ... + 6843481028.

It is an arithmetic number, because the mean of its divisors is an integer number (307956642300).

Almost surely, 2^{1218139607231} is an apocalyptic number.

1218139607231 is a deficient number, since it is larger than the sum of its proper divisors (13686961969).

1218139607231 is an equidigital number, since it uses as much as digits as its factorization.

1218139607231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13686961968.

The product of its (nonzero) digits is 108864, while the sum is 44.

The spelling of 1218139607231 in words is "one trillion, two hundred eighteen billion, one hundred thirty-nine million, six hundred seven thousand, two hundred thirty-one".