621939 has 8 divisors (see below), whose sum is σ = 832960. Its totient is φ = 412776.

The previous prime is 621937. The next prime is 621941. The reversal of 621939 is 939126.

It is an interprime number because it is at equal distance from previous prime (621937) and next prime (621941).

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

It is not a de Polignac number, because 621939 - 2¹ = 621937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621937) 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 7 ways as a sum of consecutive naturals, for example, 864 + ... + 1410.

It is an arithmetic number, because the mean of its divisors is an integer number (104120).

2⁶²¹⁹³⁹ is an apocalyptic number.

621939 is a deficient number, since it is larger than the sum of its proper divisors (211021).

621939 is a wasteful number, since it uses less digits than its factorization.

621939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929.

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

The square root of 621939 is about 788.6310924634. The cubic root of 621939 is about 85.3589892068.

It can be divided in two parts, 6 and 21939, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 621939 in words is "six hundred twenty-one thousand, nine hundred thirty-nine".