1004165621 has 2 divisors, whose sum is σ = 1004165622. Its totient is φ = 1004165620.

The previous prime is 1004165611. The next prime is 1004165633. The reversal of 1004165621 is 1265614001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 992943121 + 11222500 = 31511^2 + 3350^2 .

It is a cyclic number.

It is not a de Polignac number, because 1004165621 - 2⁶ = 1004165557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1004165611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502082810 + 502082811.

It is an arithmetic number, because the mean of its divisors is an integer number (502082811).

Almost surely, 2^1004165621 is an apocalyptic number.

It is an amenable number.

1004165621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1004165621 is an equidigital number, since it uses as much as digits as its factorization.

1004165621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1004165621 is about 31688.5724039440. The cubic root of 1004165621 is about 1001.3866167387.

Adding to 1004165621 its reverse (1265614001), we get a palindrome (2269779622).

The spelling of 1004165621 in words is "one billion, four million, one hundred sixty-five thousand, six hundred twenty-one".