1984664321 has 4 divisors (see below), whose sum is σ = 1985644500. Its totient is φ = 1983684144.

The previous prime is 1984664317. The next prime is 1984664369. The reversal of 1984664321 is 1234664891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1234664891 = 43 ⋅28713137.

It can be written as a sum of positive squares in 2 ways, for example, as 1871773696 + 112890625 = 43264^2 + 10625^2 .

It is a cyclic number.

It is not a de Polignac number, because 1984664321 - 2² = 1984664317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1984664021) 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, 487046 + ... + 491103.

It is an arithmetic number, because the mean of its divisors is an integer number (496411125).

Almost surely, 2^1984664321 is an apocalyptic number.

It is an amenable number.

1984664321 is a deficient number, since it is larger than the sum of its proper divisors (980179).

1984664321 is an equidigital number, since it uses as much as digits as its factorization.

1984664321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980178.

The product of its digits is 248832, while the sum is 44.

The square root of 1984664321 is about 44549.5715018674. The cubic root of 1984664321 is about 1256.6924929630.

The spelling of 1984664321 in words is "one billion, nine hundred eighty-four million, six hundred sixty-four thousand, three hundred twenty-one".