999681380 has 12 divisors (see below), whose sum is σ = 2099330940. Its totient is φ = 399872544.

The previous prime is 999681377. The next prime is 999681383. The reversal of 999681380 is 83186999.

It is an interprime number because it is at equal distance from previous prime (999681377) and next prime (999681383).

It can be written as a sum of positive squares in 2 ways, for example, as 760546084 + 239135296 = 27578^2 + 15464^2 .

It is a super-3 number, since 3×999681380³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (999681383) 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, 24992015 + ... + 24992054.

It is an arithmetic number, because the mean of its divisors is an integer number (174944245).

Almost surely, 2^999681380 is an apocalyptic number.

It is an amenable number.

999681380 is an abundant number, since it is smaller than the sum of its proper divisors (1099649560).

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

999681380 is a wasteful number, since it uses less digits than its factorization.

999681380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49984078 (or 49984076 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 53.

The square root of 999681380 is about 31617.7383757915. The cubic root of 999681380 is about 999.8937820515.

The spelling of 999681380 in words is "nine hundred ninety-nine million, six hundred eighty-one thousand, three hundred eighty".