621640655418 has 8 divisors (see below), whose sum is σ = 1243281310848. Its totient is φ = 207213551804.

The previous prime is 621640655417. The next prime is 621640655473. The reversal of 621640655418 is 814556046126.

It is a sphenic number, since it is the product of 3 distinct primes.

621640655418 is an admirable number.

It is a super-2 number, since 2×621640655418² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (621640655417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51803387946 + ... + 51803387957.

It is an arithmetic number, because the mean of its divisors is an integer number (155410163856).

Almost surely, 2^621640655418 is an apocalyptic number.

621640655418 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

621640655418 is a wasteful number, since it uses less digits than its factorization.

621640655418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103606775908.

The product of its (nonzero) digits is 1382400, while the sum is 48.

The spelling of 621640655418 in words is "six hundred twenty-one billion, six hundred forty million, six hundred fifty-five thousand, four hundred eighteen".