1604621 has 2 divisors, whose sum is σ = 1604622. Its totient is φ = 1604620.

The previous prime is 1604611. The next prime is 1604651. The reversal of 1604621 is 1264061.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1406596 + 198025 = 1186^2 + 445^2 .

It is an emirp because it is prime and its reverse (1264061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1604621 - 2⁶ = 1604557 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1604593 and 1604602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1604611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802310 + 802311.

It is an arithmetic number, because the mean of its divisors is an integer number (802311).

2^1604621 is an apocalyptic number.

It is an amenable number.

1604621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1604621 is an equidigital number, since it uses as much as digits as its factorization.

1604621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 1604621 is about 1266.7363577319. The cubic root of 1604621 is about 117.0732003518.

Adding to 1604621 its reverse (1264061), we get a palindrome (2868682).

The spelling of 1604621 in words is "one million, six hundred four thousand, six hundred twenty-one".