621220206853440 has 168 divisors, whose sum is σ = 2136747871258728. Its totient is φ = 165658008453120.

The previous prime is 621220206853427. The next prime is 621220206853523. The reversal of 621220206853440 is 44358602022126.

It is a happy number.

621220206853440 is a `hidden beast` number, since 6 + 2 + 1 + 2 + 20 + 206 + 85 + 344 + 0 = 666.

621220206853440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 225088568714304 + 396131638139136 = 15002952^2 + 19903056^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1335860004 + ... + 1336324956.

It is an arithmetic number, because the mean of its divisors is an integer number (12718737328921).

Almost surely, 2^{621220206853440} is an apocalyptic number.

621220206853440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

621220206853440 is an abundant number, since it is smaller than the sum of its proper divisors (1515527664405288).

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

621220206853440 is a wasteful number, since it uses less digits than its factorization.

621220206853440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 928897 (or 928884 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 45.

Adding to 621220206853440 its reverse (44358602022126), we get a palindrome (665578808875566).

The spelling of 621220206853440 in words is "six hundred twenty-one trillion, two hundred twenty billion, two hundred six million, eight hundred fifty-three thousand, four hundred forty".