1573987321 has 2 divisors, whose sum is σ = 1573987322. Its totient is φ = 1573987320.

The previous prime is 1573987243. The next prime is 1573987343. The reversal of 1573987321 is 1237893751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1298593296 + 275394025 = 36036^2 + 16595^2 .

It is a cyclic number.

It is not a de Polignac number, because 1573987321 - 2⁷ = 1573987193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1573987391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 786993660 + 786993661.

It is an arithmetic number, because the mean of its divisors is an integer number (786993661).

Almost surely, 2^1573987321 is an apocalyptic number.

It is an amenable number.

1573987321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1573987321 is an equidigital number, since it uses as much as digits as its factorization.

1573987321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 317520, while the sum is 46.

The square root of 1573987321 is about 39673.5090583124. The cubic root of 1573987321 is about 1163.2339703167.

The spelling of 1573987321 in words is "one billion, five hundred seventy-three million, nine hundred eighty-seven thousand, three hundred twenty-one".