991973579 has 8 divisors (see below), whose sum is σ = 1074751920. Its totient is φ = 911909376.

The previous prime is 991973561. The next prime is 991973597. The reversal of 991973579 is 975379199.

It is an interprime number because it is at equal distance from previous prime (991973561) and next prime (991973597).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 991973579 - 2²⁴ = 975196363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991973179) 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, 677774 + ... + 679235.

It is an arithmetic number, because the mean of its divisors is an integer number (134343990).

Almost surely, 2^991973579 is an apocalyptic number.

991973579 is a deficient number, since it is larger than the sum of its proper divisors (82778341).

991973579 is a wasteful number, since it uses less digits than its factorization.

991973579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1357069.

The product of its digits is 4822335, while the sum is 59.

The square root of 991973579 is about 31495.6120594600. The cubic root of 991973579 is about 997.3173360831.

The spelling of 991973579 in words is "nine hundred ninety-one million, nine hundred seventy-three thousand, five hundred seventy-nine".