991329075 has 72 divisors (see below), whose sum is σ = 2051024976. Its totient is φ = 452352000.

The previous prime is 991329071. The next prime is 991329077. The reversal of 991329075 is 570923199.

It is a happy number.

It is not a de Polignac number, because 991329075 - 2² = 991329071 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 991329075.

It is not an unprimeable number, because it can be changed into a prime (991329071) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 30295 + ... + 53855.

It is an arithmetic number, because the mean of its divisors is an integer number (28486458).

Almost surely, 2^991329075 is an apocalyptic number.

991329075 is the 16830-th nonagonal number.

991329075 is an abundant number, since it is smaller than the sum of its proper divisors (1059695901).

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

991329075 is a wasteful number, since it uses less digits than its factorization.

991329075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23605 (or 23597 counting only the distinct ones).

The product of its (nonzero) digits is 153090, while the sum is 45.

The square root of 991329075 is about 31485.3787495085. The cubic root of 991329075 is about 997.1012973081.

The spelling of 991329075 in words is "nine hundred ninety-one million, three hundred twenty-nine thousand, seventy-five".