1328965381 has 4 divisors (see below), whose sum is σ = 1371835264. Its totient is φ = 1286095500.

The previous prime is 1328965333. The next prime is 1328965399. The reversal of 1328965381 is 1835698231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1835698231 = 29 ⋅63299939.

It is a cyclic number.

It is not a de Polignac number, because 1328965381 - 2²⁹ = 792094469 is a prime.

It is a super-2 number, since 2×1328965381² = 3532297967792950322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1328965321) 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, 21434895 + ... + 21434956.

It is an arithmetic number, because the mean of its divisors is an integer number (342958816).

Almost surely, 2^1328965381 is an apocalyptic number.

It is an amenable number.

1328965381 is a deficient number, since it is larger than the sum of its proper divisors (42869883).

1328965381 is an equidigital number, since it uses as much as digits as its factorization.

1328965381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42869882.

The product of its digits is 311040, while the sum is 46.

The square root of 1328965381 is about 36454.9774516457. The cubic root of 1328965381 is about 1099.4392130539.

The spelling of 1328965381 in words is "one billion, three hundred twenty-eight million, nine hundred sixty-five thousand, three hundred eighty-one".