851891057 has 2 divisors, whose sum is σ = 851891058. Its totient is φ = 851891056.

The previous prime is 851891023. The next prime is 851891069. The reversal of 851891057 is 750198158.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 707506801 + 144384256 = 26599^2 + 12016^2 .

It is a cyclic number.

It is not a de Polignac number, because 851891057 - 2²⁸ = 583455601 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 851890999 and 851891017.

It is not a weakly prime, because it can be changed into another prime (851893057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425945528 + 425945529.

It is an arithmetic number, because the mean of its divisors is an integer number (425945529).

Almost surely, 2^851891057 is an apocalyptic number.

It is an amenable number.

851891057 is a deficient number, since it is larger than the sum of its proper divisors (1).

851891057 is an equidigital number, since it uses as much as digits as its factorization.

851891057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 44.

The square root of 851891057 is about 29187.1728161533. The cubic root of 851891057 is about 947.9702024526.

The spelling of 851891057 in words is "eight hundred fifty-one million, eight hundred ninety-one thousand, fifty-seven".