621438 has 8 divisors (see below), whose sum is σ = 1242888. Its totient is φ = 207144.

The previous prime is 621431. The next prime is 621443. The reversal of 621438 is 834126.

It is a happy number.

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

621438 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621431) by changing a digit.

621438 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51781 + ... + 51792.

It is an arithmetic number, because the mean of its divisors is an integer number (155361).

2⁶²¹⁴³⁸ is an apocalyptic number.

621438 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621438 is a wasteful number, since it uses less digits than its factorization.

621438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103578.

The product of its digits is 1152, while the sum is 24.

The square root of 621438 is about 788.3133894588. The cubic root of 621438 is about 85.3360628738.

The spelling of 621438 in words is "six hundred twenty-one thousand, four hundred thirty-eight".