620956561 has 3 divisors (see below), whose sum is σ = 620981481. Its totient is φ = 620931642.

The previous prime is 620956517. The next prime is 620956573. The reversal of 620956561 is 165659026.

The square root of 620956561 is 24919.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 620956561 - 2¹³ = 620948369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (620956261) by changing a digit.

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 2 ways as a sum of consecutive naturals, for example, 12460 + ... + 37378.

It is an arithmetic number, because the mean of its divisors is an integer number (206993827).

Almost surely, 2^620956561 is an apocalyptic number.

620956561 is the 24919-th square number.

620956561 is the 12460-th centered octagonal number.

It is an amenable number.

620956561 is a deficient number, since it is larger than the sum of its proper divisors (24920).

620956561 is an frugal number, since it uses more digits than its factorization.

620956561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49838 (or 24919 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 40.

The cubic root of 620956561 is about 853.1402006192.

The spelling of 620956561 in words is "six hundred twenty million, nine hundred fifty-six thousand, five hundred sixty-one".