1973621 has 4 divisors (see below), whose sum is σ = 2125452. Its totient is φ = 1821792.

The previous prime is 1973597. The next prime is 1973627. The reversal of 1973621 is 1263791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1263791 = 29 ⋅43579.

It can be written as a sum of positive squares in 2 ways, for example, as 662596 + 1311025 = 814^2 + 1145^2 .

It is a cyclic number.

It is not a de Polignac number, because 1973621 - 2⁶ = 1973557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1973627) 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, 75896 + ... + 75921.

It is an arithmetic number, because the mean of its divisors is an integer number (531363).

2^1973621 is an apocalyptic number.

It is an amenable number.

1973621 is a deficient number, since it is larger than the sum of its proper divisors (151831).

1973621 is a wasteful number, since it uses less digits than its factorization.

1973621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151830.

The product of its digits is 2268, while the sum is 29.

The square root of 1973621 is about 1404.8562204012. The cubic root of 1973621 is about 125.4357273685.

The spelling of 1973621 in words is "one million, nine hundred seventy-three thousand, six hundred twenty-one".