621688 has 8 divisors (see below), whose sum is σ = 1165680. Its totient is φ = 310840.

The previous prime is 621679. The next prime is 621697. The reversal of 621688 is 886126.

It is an interprime number because it is at equal distance from previous prime (621679) and next prime (621697).

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38848 + ... + 38863.

It is an arithmetic number, because the mean of its divisors is an integer number (145710).

2⁶²¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

621688 is a deficient number, since it is larger than the sum of its proper divisors (543992).

621688 is a wasteful number, since it uses less digits than its factorization.

621688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77717 (or 77713 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 621688 is about 788.4719398939. The cubic root of 621688 is about 85.3475046994.

The spelling of 621688 in words is "six hundred twenty-one thousand, six hundred eighty-eight".