991188130 has 16 divisors (see below), whose sum is σ = 1784503224. Its totient is φ = 396394240.

The previous prime is 991188119. The next prime is 991188131. The reversal of 991188130 is 31881199.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 990549729 + 638401 = 31473^2 + 799^2 .

It is not an unprimeable number, because it can be changed into a prime (991188131) 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 7 ways as a sum of consecutive naturals, for example, 76740 + ... + 88720.

Almost surely, 2^991188130 is an apocalyptic number.

991188130 is a deficient number, since it is larger than the sum of its proper divisors (793315094).

991188130 is a wasteful number, since it uses less digits than its factorization.

991188130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20261.

The product of its (nonzero) digits is 15552, while the sum is 40.

The square root of 991188130 is about 31483.1404087966. The cubic root of 991188130 is about 997.0540398411.

The spelling of 991188130 in words is "nine hundred ninety-one million, one hundred eighty-eight thousand, one hundred thirty".