9991400 has 24 divisors (see below), whose sum is σ = 23230470. Its totient is φ = 3996480.

The previous prime is 9991379. The next prime is 9991409. The reversal of 9991400 is 41999.

It can be written as a sum of positive squares in 3 ways, for example, as 6220036 + 3771364 = 2494^2 + 1942^2 .

It is not an unprimeable number, because it can be changed into a prime (9991409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 24779 + ... + 25178.

Almost surely, 2^9991400 is an apocalyptic number.

It is an amenable number.

9991400 is an abundant number, since it is smaller than the sum of its proper divisors (13239070).

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

9991400 is a wasteful number, since it uses less digits than its factorization.

9991400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49973 (or 49964 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 9991400 is about 3160.9175882962. The cubic root of 9991400 is about 215.3816908289.

The spelling of 9991400 in words is "nine million, nine hundred ninety-one thousand, four hundred".