851785669 has 6 divisors (see below), whose sum is σ = 990852774. Its totient is φ = 730101960.

The previous prime is 851785643. The next prime is 851785679. The reversal of 851785669 is 966587158.

It can be written as a sum of positive squares in only one way, i.e., 837813025 + 13972644 = 28945^2 + 3738^2 .

It is not a de Polignac number, because 851785669 - 2¹³ = 851777477 is a prime.

It is a super-2 number, since 2×851785669² = 1451077651827555122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851785679) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8691642 + ... + 8691739.

It is an arithmetic number, because the mean of its divisors is an integer number (165142129).

Almost surely, 2^851785669 is an apocalyptic number.

It is an amenable number.

851785669 is a deficient number, since it is larger than the sum of its proper divisors (139067105).

851785669 is a wasteful number, since it uses less digits than its factorization.

851785669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17383395 (or 17383388 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 55.

The square root of 851785669 is about 29185.3673781914. The cubic root of 851785669 is about 947.9311095025.

The spelling of 851785669 in words is "eight hundred fifty-one million, seven hundred eighty-five thousand, six hundred sixty-nine".