1311638406 has 24 divisors (see below), whose sum is σ = 2840591880. Its totient is φ = 403580736.

The previous prime is 1311638389. The next prime is 1311638407. The reversal of 1311638406 is 6048361131.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311638407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 645751 + ... + 647778.

It is an arithmetic number, because the mean of its divisors is an integer number (118357995).

Almost surely, 2^1311638406 is an apocalyptic number.

1311638406 is an abundant number, since it is smaller than the sum of its proper divisors (1528953474).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1311638406 is a wasteful number, since it uses less digits than its factorization.

1311638406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1293560 (or 1293547 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 1311638406 is about 36216.5487864319. The cubic root of 1311638406 is about 1094.6401536454.

Adding to 1311638406 its reverse (6048361131), we get a palindrome (7359999537).

The spelling of 1311638406 in words is "one billion, three hundred eleven million, six hundred thirty-eight thousand, four hundred six".