1621045 has 4 divisors (see below), whose sum is σ = 1945260. Its totient is φ = 1296832.

The previous prime is 1621043. The next prime is 1621049. The reversal of 1621045 is 5401261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5401261 = 131 ⋅41231.

It can be written as a sum of positive squares in 2 ways, for example, as 1034289 + 586756 = 1017^2 + 766^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621045 - 2¹ = 1621043 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162100 + ... + 162109.

It is an arithmetic number, because the mean of its divisors is an integer number (486315).

2^1621045 is an apocalyptic number.

It is an amenable number.

1621045 is a deficient number, since it is larger than the sum of its proper divisors (324215).

1621045 is an equidigital number, since it uses as much as digits as its factorization.

1621045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324214.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1621045 is about 1273.2026547255. The cubic root of 1621045 is about 117.4712771199.

The spelling of 1621045 in words is "one million, six hundred twenty-one thousand, forty-five".