1606621 has 4 divisors (see below), whose sum is σ = 1691200. Its totient is φ = 1522044.

The previous prime is 1606603. The next prime is 1606639. The reversal of 1606621 is 1266061.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1266061 = 557 ⋅2273.

It is an interprime number because it is at equal distance from previous prime (1606603) and next prime (1606639).

It is a cyclic number.

It is not a de Polignac number, because 1606621 - 2¹¹ = 1604573 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1606592 and 1606601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42261 + ... + 42298.

It is an arithmetic number, because the mean of its divisors is an integer number (422800).

2^1606621 is an apocalyptic number.

It is an amenable number.

1606621 is a deficient number, since it is larger than the sum of its proper divisors (84579).

1606621 is an equidigital number, since it uses as much as digits as its factorization.

1606621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84578.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 1606621 is about 1267.5255421490. The cubic root of 1606621 is about 117.1218201792.

The spelling of 1606621 in words is "one million, six hundred six thousand, six hundred twenty-one".