999565680 has 240 divisors, whose sum is σ = 3333536640. Its totient is φ = 247684608.

The previous prime is 999565667. The next prime is 999565687. The reversal of 999565680 is 86565999.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a self number, because there is not a number n which added to its sum of digits gives 999565680.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999565687) 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, 7191051 + ... + 7191189.

It is an arithmetic number, because the mean of its divisors is an integer number (13889736).

Almost surely, 2^999565680 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 999565680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1666768320).

999565680 is an abundant number, since it is smaller than the sum of its proper divisors (2333970960).

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

999565680 is a wasteful number, since it uses less digits than its factorization.

999565680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 5248800, while the sum is 57.

The square root of 999565680 is about 31615.9086537142. The cubic root of 999565680 is about 999.8552057023.

The spelling of 999565680 in words is "nine hundred ninety-nine million, five hundred sixty-five thousand, six hundred eighty".