869158821 has 4 divisors (see below), whose sum is σ = 1158878432. Its totient is φ = 579439212.

The previous prime is 869158817. The next prime is 869158841. The reversal of 869158821 is 128851968.

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.

It is not a de Polignac number, because 869158821 - 2² = 869158817 is a prime.

It is a super-2 number, since 2×869158821² = 1510874112244220082, 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 (869158841) 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, 144859801 + ... + 144859806.

It is an arithmetic number, because the mean of its divisors is an integer number (289719608).

Almost surely, 2^869158821 is an apocalyptic number.

It is an amenable number.

869158821 is a deficient number, since it is larger than the sum of its proper divisors (289719611).

869158821 is a wasteful number, since it uses less digits than its factorization.

869158821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289719610.

The product of its digits is 276480, while the sum is 48.

The square root of 869158821 is about 29481.4996396045. The cubic root of 869158821 is about 954.3324999419.

The spelling of 869158821 in words is "eight hundred sixty-nine million, one hundred fifty-eight thousand, eight hundred twenty-one".