1331186640 has 320 divisors, whose sum is σ = 5032820736. Its totient is φ = 284461056.

The previous prime is 1331186627. The next prime is 1331186653. The reversal of 1331186640 is 466811331.

It is an interprime number because it is at equal distance from previous prime (1331186627) and next prime (1331186653).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1815714 + ... + 1816446.

Almost surely, 2^1331186640 is an apocalyptic number.

1331186640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1331186640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2516410368).

1331186640 is an abundant number, since it is smaller than the sum of its proper divisors (3701634096).

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

1331186640 is a wasteful number, since it uses less digits than its factorization.

1331186640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 826 (or 820 counting only the distinct ones).

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

The square root of 1331186640 is about 36485.4305168515. The cubic root of 1331186640 is about 1100.0514135749.

Adding to 1331186640 its reverse (466811331), we get a palindrome (1797997971).

The spelling of 1331186640 in words is "one billion, three hundred thirty-one million, one hundred eighty-six thousand, six hundred forty".