991892973 has 4 divisors (see below), whose sum is σ = 1322523968. Its totient is φ = 661261980.

The previous prime is 991892971. The next prime is 991892977. The reversal of 991892973 is 379298199.

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.

It is not a de Polignac number, because 991892973 - 2¹ = 991892971 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 (991892971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165315493 + ... + 165315498.

It is an arithmetic number, because the mean of its divisors is an integer number (330630992).

Almost surely, 2^991892973 is an apocalyptic number.

It is an amenable number.

991892973 is a deficient number, since it is larger than the sum of its proper divisors (330630995).

991892973 is a wasteful number, since it uses less digits than its factorization.

991892973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330630994.

The product of its digits is 2204496, while the sum is 57.

The square root of 991892973 is about 31494.3323948929. The cubic root of 991892973 is about 997.2903219433.

The spelling of 991892973 in words is "nine hundred ninety-one million, eight hundred ninety-two thousand, nine hundred seventy-three".