991800361 has 8 divisors (see below), whose sum is σ = 1046365920. Its totient is φ = 937471392.

The previous prime is 991800353. The next prime is 991800367. The reversal of 991800361 is 163008199.

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 991800361 - 2³ = 991800353 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 991800361.

It is not an unprimeable number, because it can be changed into a prime (991800367) 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, 50500 + ... + 67333.

It is an arithmetic number, because the mean of its divisors is an integer number (130795740).

Almost surely, 2^991800361 is an apocalyptic number.

991800361 is the 16834-th nonagonal number.

It is an amenable number.

991800361 is a deficient number, since it is larger than the sum of its proper divisors (54565559).

991800361 is a wasteful number, since it uses less digits than its factorization.

991800361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118295.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 991800361 is about 31492.8620642837. The cubic root of 991800361 is about 997.2592823290.

The spelling of 991800361 in words is "nine hundred ninety-one million, eight hundred thousand, three hundred sixty-one".