993621 has 4 divisors (see below), whose sum is σ = 1324832. Its totient is φ = 662412.

The previous prime is 993617. The next prime is 993647. The reversal of 993621 is 126399.

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.

It is not a de Polignac number, because 993621 - 2² = 993617 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (993611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165601 + ... + 165606.

It is an arithmetic number, because the mean of its divisors is an integer number (331208).

2⁹⁹³⁶²¹ is an apocalyptic number.

It is an amenable number.

993621 is a deficient number, since it is larger than the sum of its proper divisors (331211).

993621 is a wasteful number, since it uses less digits than its factorization.

993621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331210.

The product of its digits is 2916, while the sum is 30.

The square root of 993621 is about 996.8053972567. The cubic root of 993621 is about 99.7869129282.

The spelling of 993621 in words is "nine hundred ninety-three thousand, six hundred twenty-one".