991849097 has 8 divisors (see below), whose sum is σ = 1035467400. Its totient is φ = 948858624.

The previous prime is 991849093. The next prime is 991849147. The reversal of 991849097 is 790948199.

It can be written as a sum of positive squares in 4 ways, for example, as 544568896 + 447280201 = 23336^2 + 21149^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 991849097 - 2² = 991849093 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991849093) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153728 + ... + 160049.

It is an arithmetic number, because the mean of its divisors is an integer number (129433425).

Almost surely, 2^991849097 is an apocalyptic number.

It is an amenable number.

991849097 is a deficient number, since it is larger than the sum of its proper divisors (43618303).

991849097 is a wasteful number, since it uses less digits than its factorization.

991849097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313915.

The product of its (nonzero) digits is 1469664, while the sum is 56.

The square root of 991849097 is about 31493.6358174156. The cubic root of 991849097 is about 997.2756168099.

The spelling of 991849097 in words is "nine hundred ninety-one million, eight hundred forty-nine thousand, ninety-seven".