691149 has 4 divisors (see below), whose sum is σ = 921536. Its totient is φ = 460764.

The previous prime is 691147. The next prime is 691151. The reversal of 691149 is 941196.

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 an interprime number because it is at equal distance from previous prime (691147) and next prime (691151).

It is not a de Polignac number, because 691149 - 2¹ = 691147 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691147) 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, 115189 + ... + 115194.

It is an arithmetic number, because the mean of its divisors is an integer number (230384).

2⁶⁹¹¹⁴⁹ is an apocalyptic number.

It is an amenable number.

691149 is a deficient number, since it is larger than the sum of its proper divisors (230387).

691149 is a wasteful number, since it uses less digits than its factorization.

691149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230386.

The product of its digits is 1944, while the sum is 30.

The square root of 691149 is about 831.3537153342. The cubic root of 691149 is about 88.4145813120.

Subtracting 691149 from its reverse (941196), we obtain a cube (250047 = 63³).

The spelling of 691149 in words is "six hundred ninety-one thousand, one hundred forty-nine".