1621673 has 8 divisors (see below), whose sum is σ = 1707720. Its totient is φ = 1537920.

The previous prime is 1621667. The next prime is 1621679. The reversal of 1621673 is 3761261.

It is an interprime number because it is at equal distance from previous prime (1621667) and next prime (1621679).

It can be written as a sum of positive squares in 4 ways, for example, as 162409 + 1459264 = 403^2 + 1208^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1621673 - 2⁴ = 1621657 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1621679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 983 + ... + 2051.

It is an arithmetic number, because the mean of its divisors is an integer number (213465).

2^1621673 is an apocalyptic number.

It is an amenable number.

1621673 is a deficient number, since it is larger than the sum of its proper divisors (86047).

1621673 is a wasteful number, since it uses less digits than its factorization.

1621673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1147.

The product of its digits is 1512, while the sum is 26.

The square root of 1621673 is about 1273.4492530132. The cubic root of 1621673 is about 117.4864447921.

The spelling of 1621673 in words is "one million, six hundred twenty-one thousand, six hundred seventy-three".