1621889 has 8 divisors (see below), whose sum is σ = 1692672. Its totient is φ = 1552320.

The previous prime is 1621877. The next prime is 1621909. The reversal of 1621889 is 9881261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621819) 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 7 ways as a sum of consecutive naturals, for example, 3272 + ... + 3734.

It is an arithmetic number, because the mean of its divisors is an integer number (211584).

2^1621889 is an apocalyptic number.

It is an amenable number.

1621889 is a deficient number, since it is larger than the sum of its proper divisors (70783).

1621889 is a wasteful number, since it uses less digits than its factorization.

1621889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607.

The product of its digits is 6912, while the sum is 35.

The square root of 1621889 is about 1273.5340592226. The cubic root of 1621889 is about 117.4916607934.

The spelling of 1621889 in words is "one million, six hundred twenty-one thousand, eight hundred eighty-nine".