1620409 has 8 divisors (see below), whose sum is σ = 1874880. Its totient is φ = 1371696.

The previous prime is 1620403. The next prime is 1620413. The reversal of 1620409 is 9040261.

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-1620409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1620409.

It is not an unprimeable number, because it can be changed into a prime (1620403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 814 + ... + 1975.

It is an arithmetic number, because the mean of its divisors is an integer number (234360).

2^1620409 is an apocalyptic number.

It is an amenable number.

1620409 is a deficient number, since it is larger than the sum of its proper divisors (254471).

1620409 is an equidigital number, since it uses as much as digits as its factorization.

1620409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2879.

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

The square root of 1620409 is about 1272.9528663702. The cubic root of 1620409 is about 117.4559122359.

The spelling of 1620409 in words is "one million, six hundred twenty thousand, four hundred nine".