621406 has 8 divisors (see below), whose sum is σ = 938520. Its totient is φ = 308568.

The previous prime is 621389. The next prime is 621419. The reversal of 621406 is 604126.

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

It is a super-2 number, since 2×621406² = 772290833672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

621406 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 676 + ... + 1303.

It is an arithmetic number, because the mean of its divisors is an integer number (117315).

2⁶²¹⁴⁰⁶ is an apocalyptic number.

621406 is a deficient number, since it is larger than the sum of its proper divisors (317114).

621406 is a wasteful number, since it uses less digits than its factorization.

621406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2138.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 621406 is about 788.2930927009. The cubic root of 621406 is about 85.3345980987.

It can be divided in two parts, 6 and 21406, that added together give a palindrome (21412).

The spelling of 621406 in words is "six hundred twenty-one thousand, four hundred six".