991949 has 4 divisors (see below), whose sum is σ = 1133664. Its totient is φ = 850236.

The previous prime is 991943. The next prime is 991951. The reversal of 991949 is 949199.

991949 = T₁₉₆ + T₁₉₇ + ... + T₂₃₇.

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.

It is a cyclic number.

It is not a de Polignac number, because 991949 - 2⁸ = 991693 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991949.

It is not an unprimeable number, because it can be changed into a prime (991943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70847 + ... + 70860.

It is an arithmetic number, because the mean of its divisors is an integer number (283416).

2⁹⁹¹⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

991949 is a deficient number, since it is larger than the sum of its proper divisors (141715).

991949 is a wasteful number, since it uses less digits than its factorization.

991949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141714.

The product of its digits is 26244, while the sum is 41.

The square root of 991949 is about 995.9663648939. The cubic root of 991949 is about 99.7309098879.

It can be divided in two parts, 99 and 1949, that added together give a 11-th power (2048 = 2¹¹).

The spelling of 991949 in words is "nine hundred ninety-one thousand, nine hundred forty-nine".