621998 has 16 divisors (see below), whose sum is σ = 1028160. Its totient is φ = 280416.

The previous prime is 621997. The next prime is 622009. The reversal of 621998 is 899126.

621998 is nontrivially palindromic in base 12.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621997) 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, 968 + ... + 1476.

It is an arithmetic number, because the mean of its divisors is an integer number (64260).

2⁶²¹⁹⁹⁸ is an apocalyptic number.

621998 is a deficient number, since it is larger than the sum of its proper divisors (406162).

621998 is a wasteful number, since it uses less digits than its factorization.

621998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571.

The product of its digits is 7776, while the sum is 35.

The square root of 621998 is about 788.6684981664. The cubic root of 621998 is about 85.3616883038.

The spelling of 621998 in words is "six hundred twenty-one thousand, nine hundred ninety-eight".