869920128 has 384 divisors, whose sum is σ = 3265142400. Its totient is φ = 225469440.

The previous prime is 869920123. The next prime is 869920157. The reversal of 869920128 is 821029968.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×869920128² = 1513522058199072768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869920123) 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, 1862551 + ... + 1863017.

It is an arithmetic number, because the mean of its divisors is an integer number (8502975).

Almost surely, 2^869920128 is an apocalyptic number.

869920128 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 869920128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1632571200).

869920128 is an abundant number, since it is smaller than the sum of its proper divisors (2395222272).

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

869920128 is a wasteful number, since it uses less digits than its factorization.

869920128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 869920128 is about 29494.4084192241. The cubic root of 869920128 is about 954.6110558551.

The spelling of 869920128 in words is "eight hundred sixty-nine million, nine hundred twenty thousand, one hundred twenty-eight".