621654 has 16 divisors (see below), whose sum is σ = 1356480. Its totient is φ = 188360.

The previous prime is 621641. The next prime is 621671. The reversal of 621654 is 456126.

It is a Curzon number.

It is a plaindrome in base 9 and base 14.

It is a congruent number.

It is an unprimeable number.

621654 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 in 7 ways as a sum of consecutive naturals, for example, 4644 + ... + 4775.

It is an arithmetic number, because the mean of its divisors is an integer number (84780).

2⁶²¹⁶⁵⁴ is an apocalyptic number.

621654 is an abundant number, since it is smaller than the sum of its proper divisors (734826).

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

621654 is a wasteful number, since it uses less digits than its factorization.

621654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9435.

The product of its digits is 1440, while the sum is 24.

The square root of 621654 is about 788.4503789079. The cubic root of 621654 is about 85.3459487913.

It can be divided in two parts, 621 and 654, that added together give a triangular number (1275 = T₅₀).

The spelling of 621654 in words is "six hundred twenty-one thousand, six hundred fifty-four".