621001 has 4 divisors (see below), whose sum is σ = 632772. Its totient is φ = 609232.

The previous prime is 620999. The next prime is 621007. The reversal of 621001 is 100126.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 164025 + 456976 = 405^2 + 676^2 .

It is a cyclic number.

It is not a de Polignac number, because 621001 - 2¹ = 620999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621007) 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, 5806 + ... + 5911.

It is an arithmetic number, because the mean of its divisors is an integer number (158193).

2⁶²¹⁰⁰¹ is an apocalyptic number.

It is an amenable number.

621001 is a deficient number, since it is larger than the sum of its proper divisors (11771).

621001 is a wasteful number, since it uses less digits than its factorization.

621001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11770.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 621001 is about 788.0361666827. The cubic root of 621001 is about 85.3160551905.

Adding to 621001 its reverse (100126), we get a palindrome (721127).

The spelling of 621001 in words is "six hundred twenty-one thousand, one".