991395201 has 4 divisors (see below), whose sum is σ = 1321860272. Its totient is φ = 660930132.

The previous prime is 991395199. The next prime is 991395203. The reversal of 991395201 is 102593199.

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: 102593199 = 3 ⋅34197733.

It is an interprime number because it is at equal distance from previous prime (991395199) and next prime (991395203).

It is not a de Polignac number, because 991395201 - 2¹ = 991395199 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 991395201.

It is not an unprimeable number, because it can be changed into a prime (991395203) 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, 165232531 + ... + 165232536.

It is an arithmetic number, because the mean of its divisors is an integer number (330465068).

Almost surely, 2^991395201 is an apocalyptic number.

It is an amenable number.

991395201 is a deficient number, since it is larger than the sum of its proper divisors (330465071).

991395201 is a wasteful number, since it uses less digits than its factorization.

991395201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330465070.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 991395201 is about 31486.4288384694. The cubic root of 991395201 is about 997.1234671594.

The spelling of 991395201 in words is "nine hundred ninety-one million, three hundred ninety-five thousand, two hundred one".