851621000501 has 2 divisors, whose sum is σ = 851621000502. Its totient is φ = 851621000500.

The previous prime is 851621000491. The next prime is 851621000551. The reversal of 851621000501 is 105000126158.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 725861400625 + 125759599876 = 851975^2 + 354626^2 .

It is a cyclic number.

It is not a de Polignac number, because 851621000501 - 2¹⁰ = 851620999477 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (851621000551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425810500250 + 425810500251.

It is an arithmetic number, because the mean of its divisors is an integer number (425810500251).

Almost surely, 2^851621000501 is an apocalyptic number.

It is an amenable number.

851621000501 is a deficient number, since it is larger than the sum of its proper divisors (1).

851621000501 is an equidigital number, since it uses as much as digits as its factorization.

851621000501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 29.

Adding to 851621000501 its reverse (105000126158), we get a palindrome (956621126659).

The spelling of 851621000501 in words is "eight hundred fifty-one billion, six hundred twenty-one million, five hundred one", and thus it is an aban number.