869821281 has 48 divisors (see below), whose sum is σ = 1522070400. Its totient is φ = 480906720.

The previous prime is 869821261. The next prime is 869821289. The reversal of 869821281 is 182128968.

It is a happy number.

It is not a de Polignac number, because 869821281 - 2⁶ = 869821217 is a prime.

It is a super-2 number, since 2×869821281² = 1513178121760961922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (869821289) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 179235 + ... + 184023.

It is an arithmetic number, because the mean of its divisors is an integer number (31709800).

Almost surely, 2^869821281 is an apocalyptic number.

It is an amenable number.

869821281 is a deficient number, since it is larger than the sum of its proper divisors (652249119).

869821281 is a wasteful number, since it uses less digits than its factorization.

869821281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4867 (or 4830 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 869821281 is about 29492.7326811199. The cubic root of 869821281 is about 954.5748977412.

The spelling of 869821281 in words is "eight hundred sixty-nine million, eight hundred twenty-one thousand, two hundred eighty-one".