991377044 has 12 divisors (see below), whose sum is σ = 1982754144. Its totient is φ = 424875864.

The previous prime is 991376999. The next prime is 991377053. The reversal of 991377044 is 440773199.

It is a happy number.

991377044 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 991376986 and 991377004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17703134 + ... + 17703189.

It is an arithmetic number, because the mean of its divisors is an integer number (165229512).

Almost surely, 2^991377044 is an apocalyptic number.

It is an amenable number.

991377044 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991377044 is a wasteful number, since it uses less digits than its factorization.

991377044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35406334 (or 35406332 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 44.

The square root of 991377044 is about 31486.1405065784. The cubic root of 991377044 is about 997.1173798186.

The spelling of 991377044 in words is "nine hundred ninety-one million, three hundred seventy-seven thousand, forty-four".