1620663 has 16 divisors (see below), whose sum is σ = 2395776. Its totient is φ = 966240.

The previous prime is 1620631. The next prime is 1620667. The reversal of 1620663 is 3660261.

It is not a de Polignac number, because 1620663 - 2⁵ = 1620631 is a prime.

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 (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1845 + ... + 2577.

It is an arithmetic number, because the mean of its divisors is an integer number (149736).

2^1620663 is an apocalyptic number.

1620663 is a deficient number, since it is larger than the sum of its proper divisors (775113).

1620663 is a wasteful number, since it uses less digits than its factorization.

1620663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 1620663 is about 1273.0526304910. The cubic root of 1620663 is about 117.4620490082.

The spelling of 1620663 in words is "one million, six hundred twenty thousand, six hundred sixty-three".