1326380991 has 16 divisors (see below), whose sum is σ = 1908910080. Its totient is φ = 814364640.

The previous prime is 1326380963. The next prime is 1326380999. The reversal of 1326380991 is 1990836231.

It is not a de Polignac number, because 1326380991 - 2⁶ = 1326380927 is a prime.

It is a super-2 number, since 2×1326380991² = 3518573066572284162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1326380999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21615 + ... + 55856.

It is an arithmetic number, because the mean of its divisors is an integer number (119306880).

Almost surely, 2^1326380991 is an apocalyptic number.

1326380991 is a deficient number, since it is larger than the sum of its proper divisors (582529089).

1326380991 is a wasteful number, since it uses less digits than its factorization.

1326380991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77926.

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 1326380991 is about 36419.5138764921. The cubic root of 1326380991 is about 1098.7260709403.

The spelling of 1326380991 in words is "one billion, three hundred twenty-six million, three hundred eighty thousand, nine hundred ninety-one".