869920 has 24 divisors (see below), whose sum is σ = 2055564. Its totient is φ = 347904.

The previous prime is 869909. The next prime is 869927. The reversal of 869920 is 29968.

It can be written as a sum of positive squares in 2 ways, for example, as 868624 + 1296 = 932^2 + 36^2 .

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (869927) by changing a digit.

869920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2559 + ... + 2878.

2⁸⁶⁹⁹²⁰ is an apocalyptic number.

869920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

869920 is an abundant number, since it is smaller than the sum of its proper divisors (1185644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

869920 is a wasteful number, since it uses less digits than its factorization.

869920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5452 (or 5444 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 869920 is about 932.6950198216. The cubic root of 869920 is about 95.4611009035.

It can be divided in two parts, 869 and 920, that multiplied together give a triangular number (799480 = T₁₂₆₄).

The spelling of 869920 in words is "eight hundred sixty-nine thousand, nine hundred twenty".