620857997 has 2 divisors, whose sum is σ = 620857998. Its totient is φ = 620857996.

The previous prime is 620857961. The next prime is 620857999. The reversal of 620857997 is 799758026.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 343768681 + 277089316 = 18541^2 + 16646^2 .

It is a cyclic number.

It is not a de Polignac number, because 620857997 - 2⁶ = 620857933 is a prime.

Together with 620857999, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (620857999) 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 as a sum of consecutive naturals, namely, 310428998 + 310428999.

It is an arithmetic number, because the mean of its divisors is an integer number (310428999).

Almost surely, 2^620857997 is an apocalyptic number.

It is an amenable number.

620857997 is a deficient number, since it is larger than the sum of its proper divisors (1).

620857997 is an equidigital number, since it uses as much as digits as its factorization.

620857997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1905120, while the sum is 53.

The square root of 620857997 is about 24917.0222338064. The cubic root of 620857997 is about 853.0950587818.

The spelling of 620857997 in words is "six hundred twenty million, eight hundred fifty-seven thousand, nine hundred ninety-seven".