1620909 has 12 divisors (see below), whose sum is σ = 2464800. Its totient is φ = 1023624.

The previous prime is 1620893. The next prime is 1620917. The reversal of 1620909 is 9090261.

It is a happy number.

It is not a de Polignac number, because 1620909 - 2⁴ = 1620893 is a prime.

1620909 is a modest number, since divided by 909 gives 162 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4569 + ... + 4910.

It is an arithmetic number, because the mean of its divisors is an integer number (205400).

2^1620909 is an apocalyptic number.

1620909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1620909 is a deficient number, since it is larger than the sum of its proper divisors (843891).

1620909 is a wasteful number, since it uses less digits than its factorization.

1620909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9504 (or 9501 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 1620909 is about 1273.1492449827. The cubic root of 1620909 is about 117.4679918851.

The spelling of 1620909 in words is "one million, six hundred twenty thousand, nine hundred nine".