991544677 has 4 divisors (see below), whose sum is σ = 992505580. Its totient is φ = 990583776.

The previous prime is 991544663. The next prime is 991544681. The reversal of 991544677 is 776445199.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 785736961 + 205807716 = 28031^2 + 14346^2 .

It is a cyclic number.

It is not a de Polignac number, because 991544677 - 2¹⁵ = 991511909 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 (991544657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 478902 + ... + 480967.

It is an arithmetic number, because the mean of its divisors is an integer number (248126395).

Almost surely, 2^991544677 is an apocalyptic number.

It is an amenable number.

991544677 is a deficient number, since it is larger than the sum of its proper divisors (960903).

991544677 is a wasteful number, since it uses less digits than its factorization.

991544677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 960902.

The product of its digits is 1905120, while the sum is 52.

The square root of 991544677 is about 31488.8024065699. The cubic root of 991544677 is about 997.1735778644.

The spelling of 991544677 in words is "nine hundred ninety-one million, five hundred forty-four thousand, six hundred seventy-seven".