1620845 has 8 divisors (see below), whose sum is σ = 1956960. Its totient is φ = 1288720.

The previous prime is 1620841. The next prime is 1620881. The reversal of 1620845 is 5480261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1620845 - 2² = 1620841 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620841) 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 7 ways as a sum of consecutive naturals, for example, 11 + ... + 1800.

It is an arithmetic number, because the mean of its divisors is an integer number (244620).

2^1620845 is an apocalyptic number.

It is an amenable number.

1620845 is a deficient number, since it is larger than the sum of its proper divisors (336115).

1620845 is a wasteful number, since it uses less digits than its factorization.

1620845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 1620845 is about 1273.1241102108. The cubic root of 1620845 is about 117.4664458286.

It can be divided in two parts, 1620 and 845, that multiplied together give a square (1368900 = 1170²).

The spelling of 1620845 in words is "one million, six hundred twenty thousand, eight hundred forty-five".