851773121 has 4 divisors (see below), whose sum is σ = 852935892. Its totient is φ = 850610352.

The previous prime is 851773067. The next prime is 851773171. The reversal of 851773121 is 121377158.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 498896896 + 352876225 = 22336^2 + 18785^2 .

It is a cyclic number.

It is not a de Polignac number, because 851773121 - 2²² = 847578817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (851773171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 580286 + ... + 581751.

It is an arithmetic number, because the mean of its divisors is an integer number (213233973).

Almost surely, 2^851773121 is an apocalyptic number.

It is an amenable number.

851773121 is a deficient number, since it is larger than the sum of its proper divisors (1162771).

851773121 is a wasteful number, since it uses less digits than its factorization.

851773121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1162770.

The product of its digits is 11760, while the sum is 35.

The square root of 851773121 is about 29185.1524066605. The cubic root of 851773121 is about 947.9264546938.

The spelling of 851773121 in words is "eight hundred fifty-one million, seven hundred seventy-three thousand, one hundred twenty-one".