991377 has 12 divisors (see below), whose sum is σ = 1457040. Its totient is φ = 649368.

The previous prime is 991357. The next prime is 991381. The reversal of 991377 is 773199.

It is not a de Polignac number, because 991377 - 2⁶ = 991313 is a prime.

It is a super-2 number, since 2×991377² = 1965656712258, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991377.

It is not an unprimeable number, because it can be changed into a prime (991327) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 403 + ... + 1464.

It is an arithmetic number, because the mean of its divisors is an integer number (121420).

2⁹⁹¹³⁷⁷ is an apocalyptic number.

It is an amenable number.

991377 is a deficient number, since it is larger than the sum of its proper divisors (465663).

991377 is a wasteful number, since it uses less digits than its factorization.

991377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932 (or 1929 counting only the distinct ones).

The product of its digits is 11907, while the sum is 36.

The square root of 991377 is about 995.6791651933. The cubic root of 991377 is about 99.7117365067.

The spelling of 991377 in words is "nine hundred ninety-one thousand, three hundred seventy-seven".