815871616 has 128 divisors (see below), whose sum is σ = 2035756800. Its totient is φ = 317571072.

The previous prime is 815871613. The next prime is 815871619. The reversal of 815871616 is 616178518.

It is an interprime number because it is at equal distance from previous prime (815871613) and next prime (815871619).

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (815871611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 440805 + ... + 442651.

It is an arithmetic number, because the mean of its divisors is an integer number (15904350).

Almost surely, 2^815871616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 815871616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1017878400).

815871616 is an abundant number, since it is smaller than the sum of its proper divisors (1219885184).

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

815871616 is a wasteful number, since it uses less digits than its factorization.

815871616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1914 (or 1902 counting only the distinct ones).

The product of its digits is 80640, while the sum is 43.

The square root of 815871616 is about 28563.4664562969. The cubic root of 815871616 is about 934.4167355638.

The spelling of 815871616 in words is "eight hundred fifteen million, eight hundred seventy-one thousand, six hundred sixteen".