1620664 has 16 divisors (see below), whose sum is σ = 3058920. Its totient is φ = 804960.

The previous prime is 1620631. The next prime is 1620667. The reversal of 1620664 is 4660261.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620667) 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, 799 + ... + 1969.

2^1620664 is an apocalyptic number.

It is an amenable number.

1620664 is a deficient number, since it is larger than the sum of its proper divisors (1438256).

1620664 is a wasteful number, since it uses less digits than its factorization.

1620664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1350 (or 1346 counting only the distinct ones).

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

The square root of 1620664 is about 1273.0530232477. The cubic root of 1620664 is about 117.4620731674.

The spelling of 1620664 in words is "one million, six hundred twenty thousand, six hundred sixty-four".