1329623921 has 4 divisors (see below), whose sum is σ = 1330076532. Its totient is φ = 1329171312.

The previous prime is 1329623917. The next prime is 1329623927. The reversal of 1329623921 is 1293269231.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 246490000 + 1083133921 = 15700^2 + 32911^2 .

It is a cyclic number.

It is not a de Polignac number, because 1329623921 - 2² = 1329623917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1329623927) 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, 221870 + ... + 227783.

It is an arithmetic number, because the mean of its divisors is an integer number (332519133).

Almost surely, 2^1329623921 is an apocalyptic number.

It is an amenable number.

1329623921 is a deficient number, since it is larger than the sum of its proper divisors (452611).

1329623921 is an equidigital number, since it uses as much as digits as its factorization.

1329623921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452610.

The product of its digits is 34992, while the sum is 38.

The square root of 1329623921 is about 36464.0085700955. The cubic root of 1329623921 is about 1099.6207841596.

The spelling of 1329623921 in words is "one billion, three hundred twenty-nine million, six hundred twenty-three thousand, nine hundred twenty-one".