991332073 has 2 divisors, whose sum is σ = 991332074. Its totient is φ = 991332072.

The previous prime is 991332047. The next prime is 991332103. The reversal of 991332073 is 370233199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640444249 + 350887824 = 25307^2 + 18732^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991332073 is a prime.

It is not a weakly prime, because it can be changed into another prime (991332673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495666036 + 495666037.

It is an arithmetic number, because the mean of its divisors is an integer number (495666037).

Almost surely, 2^991332073 is an apocalyptic number.

It is an amenable number.

991332073 is a deficient number, since it is larger than the sum of its proper divisors (1).

991332073 is an equidigital number, since it uses as much as digits as its factorization.

991332073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30618, while the sum is 37.

The square root of 991332073 is about 31485.4263588728. The cubic root of 991332073 is about 997.1023024593.

The spelling of 991332073 in words is "nine hundred ninety-one million, three hundred thirty-two thousand, seventy-three".