851874368581 has 2 divisors, whose sum is σ = 851874368582. Its totient is φ = 851874368580.

The previous prime is 851874368551. The next prime is 851874368593. The reversal of 851874368581 is 185863478158.

851874368581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 755256593025 + 96617775556 = 869055^2 + 310834^2 .

It is a cyclic number.

It is not a de Polignac number, because 851874368581 - 2⁵ = 851874368549 is a prime.

It is a super-2 number, since 2×851874368581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (851874368551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425937184290 + 425937184291.

It is an arithmetic number, because the mean of its divisors is an integer number (425937184291).

Almost surely, 2^851874368581 is an apocalyptic number.

It is an amenable number.

851874368581 is a deficient number, since it is larger than the sum of its proper divisors (1).

851874368581 is an equidigital number, since it uses as much as digits as its factorization.

851874368581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51609600, while the sum is 64.

The spelling of 851874368581 in words is "eight hundred fifty-one billion, eight hundred seventy-four million, three hundred sixty-eight thousand, five hundred eighty-one".