1620863 has 4 divisors (see below), whose sum is σ = 1633368. Its totient is φ = 1608360.

The previous prime is 1620841. The next prime is 1620881. The reversal of 1620863 is 3680261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3680261 = 13 ⋅283097.

It is a cyclic number.

It is not a de Polignac number, because 1620863 - 2¹⁴ = 1604479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6056 + ... + 6317.

It is an arithmetic number, because the mean of its divisors is an integer number (408342).

2^1620863 is an apocalyptic number.

1620863 is a deficient number, since it is larger than the sum of its proper divisors (12505).

1620863 is a wasteful number, since it uses less digits than its factorization.

1620863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12504.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 1620863 is about 1273.1311794155. The cubic root of 1620863 is about 117.4668806611.

The spelling of 1620863 in words is "one million, six hundred twenty thousand, eight hundred sixty-three".