851281 has 4 divisors (see below), whose sum is σ = 858112. Its totient is φ = 844452.

The previous prime is 851273. The next prime is 851293. The reversal of 851281 is 182158.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 182158 = 2 ⋅91079.

It is a cyclic number.

It is not a de Polignac number, because 851281 - 2³ = 851273 is a prime.

It is a super-2 number, since 2×851281² = 1449358681922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (851231) 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, 3225 + ... + 3478.

It is an arithmetic number, because the mean of its divisors is an integer number (214528).

2⁸⁵¹²⁸¹ is an apocalyptic number.

It is an amenable number.

851281 is a deficient number, since it is larger than the sum of its proper divisors (6831).

851281 is a wasteful number, since it uses less digits than its factorization.

851281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6830.

The product of its digits is 640, while the sum is 25.

The square root of 851281 is about 922.6489039716. The cubic root of 851281 is about 94.7743861320.

The spelling of 851281 in words is "eight hundred fifty-one thousand, two hundred eighty-one".