1620447 has 4 divisors (see below), whose sum is σ = 2160600. Its totient is φ = 1080296.

The previous prime is 1620439. The next prime is 1620449. The reversal of 1620447 is 7440261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7440261 = 3 ⋅2480087.

It is a cyclic number.

It is not a de Polignac number, because 1620447 - 2³ = 1620439 is a prime.

It is a D-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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270072 + ... + 270077.

It is an arithmetic number, because the mean of its divisors is an integer number (540150).

2^1620447 is an apocalyptic number.

1620447 is a deficient number, since it is larger than the sum of its proper divisors (540153).

1620447 is an equidigital number, since it uses as much as digits as its factorization.

1620447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540152.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 1620447 is about 1272.9677922084. The cubic root of 1620447 is about 117.4568303765.

The spelling of 1620447 in words is "one million, six hundred twenty thousand, four hundred forty-seven".