621866358828 has 192 divisors, whose sum is σ = 1934409738240. Its totient is φ = 170247398400.

The previous prime is 621866358809. The next prime is 621866358829. The reversal of 621866358828 is 828853668126.

621866358828 is a `hidden beast` number, since 6 + 21 + 8 + 6 + 6 + 3 + 588 + 28 = 666.

It is not an unprimeable number, because it can be changed into a prime (621866358829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 297508 + ... + 1154228.

It is an arithmetic number, because the mean of its divisors is an integer number (10075050720).

Almost surely, 2^621866358828 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621866358828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (967204869120).

621866358828 is an abundant number, since it is smaller than the sum of its proper divisors (1312543379412).

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

621866358828 is a wasteful number, since it uses less digits than its factorization.

621866358828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 856805 (or 856797 counting only the distinct ones).

The product of its digits is 53084160, while the sum is 63.

The spelling of 621866358828 in words is "six hundred twenty-one billion, eight hundred sixty-six million, three hundred fifty-eight thousand, eight hundred twenty-eight".