1620646 has 16 divisors (see below), whose sum is σ = 2511648. Its totient is φ = 784000.

The previous prime is 1620631. The next prime is 1620667. The reversal of 1620646 is 6460261.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1620646.

It is a congruent number.

It is an unprimeable number.

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, 14286 + ... + 14398.

It is an arithmetic number, because the mean of its divisors is an integer number (156978).

2^1620646 is an apocalyptic number.

1620646 is a deficient number, since it is larger than the sum of its proper divisors (891002).

1620646 is a wasteful number, since it uses less digits than its factorization.

1620646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1620646 is about 1273.0459536089. The cubic root of 1620646 is about 117.4616382993.

The spelling of 1620646 in words is "one million, six hundred twenty thousand, six hundred forty-six".