691963 has 4 divisors (see below), whose sum is σ = 695968. Its totient is φ = 687960.

The previous prime is 691949. The next prime is 691973. The reversal of 691963 is 369196.

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

It is a cyclic number.

It is not a de Polignac number, because 691963 - 2⁵ = 691931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1731 + ... + 2092.

It is an arithmetic number, because the mean of its divisors is an integer number (173992).

2⁶⁹¹⁹⁶³ is an apocalyptic number.

691963 is a deficient number, since it is larger than the sum of its proper divisors (4005).

691963 is a wasteful number, since it uses less digits than its factorization.

691963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4004.

The product of its digits is 8748, while the sum is 34.

The square root of 691963 is about 831.8431342507. The cubic root of 691963 is about 88.4492777540.

The spelling of 691963 in words is "six hundred ninety-one thousand, nine hundred sixty-three".