620555450343661 has 6 divisors (see below), whose sum is σ = 721870625910030. Its totient is φ = 531904671723096.

The previous prime is 620555450343581. The next prime is 620555450343671. The reversal of 620555450343661 is 166343054555026.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 478130440045636 + 142425010298025 = 21866194^2 + 11934195^2 .

It is not a de Polignac number, because 620555450343661 - 2¹¹ = 620555450341613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620555450343671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6332198472846 + ... + 6332198472943.

It is an arithmetic number, because the mean of its divisors is an integer number (120311770985005).

Almost surely, 2^{620555450343661} is an apocalyptic number.

It is an amenable number.

620555450343661 is a deficient number, since it is larger than the sum of its proper divisors (101315175566369).

620555450343661 is a wasteful number, since it uses less digits than its factorization.

620555450343661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12664396945803 (or 12664396945796 counting only the distinct ones).

The product of its (nonzero) digits is 38880000, while the sum is 55.

The spelling of 620555450343661 in words is "six hundred twenty trillion, five hundred fifty-five billion, four hundred fifty million, three hundred forty-three thousand, six hundred sixty-one".