621856 has 12 divisors (see below), whose sum is σ = 1224342. Its totient is φ = 310912.

The previous prime is 621833. The next prime is 621869. The reversal of 621856 is 658126.

It can be written as a sum of positive squares in only one way, i.e., 608400 + 13456 = 780^2 + 116^2 .

It is an unprimeable number.

621856 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 as a sum of consecutive naturals, namely, 9685 + ... + 9748.

2⁶²¹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

621856 is a deficient number, since it is larger than the sum of its proper divisors (602486).

621856 is a wasteful number, since it uses less digits than its factorization.

621856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19443 (or 19435 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 621856 is about 788.5784678775. The cubic root of 621856 is about 85.3551918830.

The spelling of 621856 in words is "six hundred twenty-one thousand, eight hundred fifty-six".