1621453 has 4 divisors (see below), whose sum is σ = 1656000. Its totient is φ = 1586908.

The previous prime is 1621439. The next prime is 1621457. The reversal of 1621453 is 3541261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3541261 = 467 ⋅7583.

It is not a de Polignac number, because 1621453 - 2⁵ = 1621421 is a prime.

It is a Duffinian number.

1621453 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621457) 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, 17203 + ... + 17296.

It is an arithmetic number, because the mean of its divisors is an integer number (414000).

2^1621453 is an apocalyptic number.

It is an amenable number.

1621453 is a deficient number, since it is larger than the sum of its proper divisors (34547).

1621453 is an equidigital number, since it uses as much as digits as its factorization.

1621453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34546.

The product of its digits is 720, while the sum is 22.

The square root of 1621453 is about 1273.3628705126. The cubic root of 1621453 is about 117.4811317220.

The spelling of 1621453 in words is "one million, six hundred twenty-one thousand, four hundred fifty-three".