891308997 has 24 divisors (see below), whose sum is σ = 1410191640. Its totient is φ = 539965440.

The previous prime is 891308983. The next prime is 891309007. The reversal of 891308997 is 799803198.

It can be written as a sum of positive squares in 4 ways, for example, as 428241636 + 463067361 = 20694^2 + 21519^2 .

It is not a de Polignac number, because 891308997 - 2¹⁴ = 891292613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891308927) 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 23 ways as a sum of consecutive naturals, for example, 96004 + ... + 104877.

It is an arithmetic number, because the mean of its divisors is an integer number (58757985).

Almost surely, 2^891308997 is an apocalyptic number.

891308997 is a gapful number since it is divisible by the number (87) formed by its first and last digit.

It is an amenable number.

891308997 is a deficient number, since it is larger than the sum of its proper divisors (518882643).

891308997 is a wasteful number, since it uses less digits than its factorization.

891308997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200933 (or 200930 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The square root of 891308997 is about 29854.7985590256. The cubic root of 891308997 is about 962.3715227849.

The spelling of 891308997 in words is "eight hundred ninety-one million, three hundred eight thousand, nine hundred ninety-seven".