1620965 has 8 divisors (see below), whose sum is σ = 1972248. Its totient is φ = 1278720.

The previous prime is 1620961. The next prime is 1620973. The reversal of 1620965 is 5690261.

It can be written as a sum of positive squares in 4 ways, for example, as 139876 + 1481089 = 374^2 + 1217^2 .

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

It is not a de Polignac number, because 1620965 - 2² = 1620961 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 (1620961) 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, 1856 + ... + 2585.

It is an arithmetic number, because the mean of its divisors is an integer number (246531).

2^1620965 is an apocalyptic number.

It is an amenable number.

1620965 is a deficient number, since it is larger than the sum of its proper divisors (351283).

1620965 is an equidigital number, since it uses as much as digits as its factorization.

1620965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4519.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 1620965 is about 1273.1712375011. The cubic root of 1620965 is about 117.4693446511.

The spelling of 1620965 in words is "one million, six hundred twenty thousand, nine hundred sixty-five".