1311940718978 has 4 divisors (see below), whose sum is σ = 1967911078470. Its totient is φ = 655970359488.

The previous prime is 1311940718951. The next prime is 1311940718981. The reversal of 1311940718978 is 8798170491131.

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

It can be written as a sum of positive squares in only one way, i.e., 925649879449 + 386290839529 = 962107^2 + 621523^2 .

It is a super-2 number, since 2×1311940718978² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327985179743 + ... + 327985179746.

Almost surely, 2^{1311940718978} is an apocalyptic number.

1311940718978 is a deficient number, since it is larger than the sum of its proper divisors (655970359492).

1311940718978 is an equidigital number, since it uses as much as digits as its factorization.

1311940718978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655970359491.

The product of its (nonzero) digits is 3048192, while the sum is 59.

The spelling of 1311940718978 in words is "one trillion, three hundred eleven billion, nine hundred forty million, seven hundred eighteen thousand, nine hundred seventy-eight".