1318021636 has 12 divisors (see below), whose sum is σ = 2310140700. Its totient is φ = 657981440.

The previous prime is 1318021633. The next prime is 1318021651. The reversal of 1318021636 is 6361208131.

It can be written as a sum of positive squares in 2 ways, for example, as 967583236 + 350438400 = 31106^2 + 18720^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1318021598 and 1318021607.

It is not an unprimeable number, because it can be changed into a prime (1318021631) 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, 254461 + ... + 259588.

It is an arithmetic number, because the mean of its divisors is an integer number (192511725).

Almost surely, 2^1318021636 is an apocalyptic number.

It is an amenable number.

1318021636 is a deficient number, since it is larger than the sum of its proper divisors (992119064).

1318021636 is a wasteful number, since it uses less digits than its factorization.

1318021636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514694 (or 514692 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 1318021636 is about 36304.5677015992. The cubic root of 1318021636 is about 1096.4130090048.

Adding to 1318021636 its reverse (6361208131), we get a palindrome (7679229767).

The spelling of 1318021636 in words is "one billion, three hundred eighteen million, twenty-one thousand, six hundred thirty-six".