1000399680 has 672 divisors, whose sum is σ = 4378147200. Its totient is φ = 213663744.

The previous prime is 1000399637. The next prime is 1000399681. The reversal of 1000399680 is 869930001.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000399681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7197051 + ... + 7197189.

It is an arithmetic number, because the mean of its divisors is an integer number (6515100).

Almost surely, 2^1000399680 is an apocalyptic number.

1000399680 is a gapful number since it is divisible by the number (10) 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 1000399680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2189073600).

1000399680 is an abundant number, since it is smaller than the sum of its proper divisors (3377747520).

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

1000399680 is a wasteful number, since it uses less digits than its factorization.

1000399680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1000399680 is about 31629.0954660420. The cubic root of 1000399680 is about 1000.1332089213.

The spelling of 1000399680 in words is "one billion, three hundred ninety-nine thousand, six hundred eighty".