1604506621 has 2 divisors, whose sum is σ = 1604506622. Its totient is φ = 1604506620.

The previous prime is 1604506571. The next prime is 1604506627. The reversal of 1604506621 is 1266054061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1155660025 + 448846596 = 33995^2 + 21186^2 .

It is a cyclic number.

It is not a de Polignac number, because 1604506621 - 2⁹ = 1604506109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1604506627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802253310 + 802253311.

It is an arithmetic number, because the mean of its divisors is an integer number (802253311).

Almost surely, 2^1604506621 is an apocalyptic number.

It is an amenable number.

1604506621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1604506621 is an equidigital number, since it uses as much as digits as its factorization.

1604506621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 1604506621 is about 40056.2931510144. The cubic root of 1604506621 is about 1170.7041858719.

The spelling of 1604506621 in words is "one billion, six hundred four million, five hundred six thousand, six hundred twenty-one".