1620445 has 4 divisors (see below), whose sum is σ = 1944540. Its totient is φ = 1296352.

The previous prime is 1620439. The next prime is 1620449. The reversal of 1620445 is 5440261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5440261 = 461 ⋅11801.

It can be written as a sum of positive squares in 2 ways, for example, as 749956 + 870489 = 866^2 + 933^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620445 - 2⁵ = 1620413 is a prime.

1620445 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620449) 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 3 ways as a sum of consecutive naturals, for example, 162040 + ... + 162049.

It is an arithmetic number, because the mean of its divisors is an integer number (486135).

2^1620445 is an apocalyptic number.

It is an amenable number.

1620445 is a deficient number, since it is larger than the sum of its proper divisors (324095).

1620445 is an equidigital number, since it uses as much as digits as its factorization.

1620445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324094.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1620445 is about 1272.9670066424. The cubic root of 1620445 is about 117.4567820536.

The spelling of 1620445 in words is "one million, six hundred twenty thousand, four hundred forty-five".