1329797981 has 4 divisors (see below), whose sum is σ = 1337227200. Its totient is φ = 1322368764.

The previous prime is 1329797939. The next prime is 1329797993. The reversal of 1329797981 is 1897979231.

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.

It is a cyclic number.

It is not a de Polignac number, because 1329797981 - 2¹⁴ = 1329781597 is a prime.

It is a super-2 number, since 2×1329797981² = 3536725340543352722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1329797921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3714341 + ... + 3714698.

It is an arithmetic number, because the mean of its divisors is an integer number (334306800).

Almost surely, 2^1329797981 is an apocalyptic number.

It is an amenable number.

1329797981 is a deficient number, since it is larger than the sum of its proper divisors (7429219).

1329797981 is an equidigital number, since it uses as much as digits as its factorization.

1329797981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7429218.

The product of its digits is 1714608, while the sum is 56.

The square root of 1329797981 is about 36466.3952290324. The cubic root of 1329797981 is about 1099.6687655572.

The spelling of 1329797981 in words is "one billion, three hundred twenty-nine million, seven hundred ninety-seven thousand, nine hundred eighty-one".