990309797 has 4 divisors (see below), whose sum is σ = 990453696. Its totient is φ = 990165900.

The previous prime is 990309767. The next prime is 990309829. The reversal of 990309797 is 797903099.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 797903099 = 7 ⋅113986157.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990309797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990309767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61079 + ... + 75572.

It is an arithmetic number, because the mean of its divisors is an integer number (247613424).

Almost surely, 2^990309797 is an apocalyptic number.

It is an amenable number.

990309797 is a deficient number, since it is larger than the sum of its proper divisors (143899).

990309797 is a wasteful number, since it uses less digits than its factorization.

990309797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143898.

The product of its (nonzero) digits is 964467, while the sum is 53.

The square root of 990309797 is about 31469.1880575270. The cubic root of 990309797 is about 996.7594424634.

The spelling of 990309797 in words is "nine hundred ninety million, three hundred nine thousand, seven hundred ninety-seven".