1621073 has 4 divisors (see below), whose sum is σ = 1640688. Its totient is φ = 1601460.

The previous prime is 1621049. The next prime is 1621079. The reversal of 1621073 is 3701261.

It is a happy number.

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: 3701261 = 787 ⋅4703.

It is a cyclic number.

It is not a de Polignac number, because 1621073 - 2²⁰ = 572497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1621079) 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, 9683 + ... + 9848.

It is an arithmetic number, because the mean of its divisors is an integer number (410172).

2^1621073 is an apocalyptic number.

It is an amenable number.

1621073 is a deficient number, since it is larger than the sum of its proper divisors (19615).

1621073 is an equidigital number, since it uses as much as digits as its factorization.

1621073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19614.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 1621073 is about 1273.2136505709. The cubic root of 1621073 is about 117.4719534690.

The spelling of 1621073 in words is "one million, six hundred twenty-one thousand, seventy-three".