691039 has 4 divisors (see below), whose sum is σ = 693000. Its totient is φ = 689080.

The previous prime is 691037. The next prime is 691051. The reversal of 691039 is 930196.

It is a happy number.

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 691039 - 2¹ = 691037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 690998 and 691016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691037) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 289 + ... + 1210.

It is an arithmetic number, because the mean of its divisors is an integer number (173250).

2⁶⁹¹⁰³⁹ is an apocalyptic number.

691039 is a deficient number, since it is larger than the sum of its proper divisors (1961).

691039 is a wasteful number, since it uses less digits than its factorization.

691039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1960.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 691039 is about 831.2875555426. The cubic root of 691039 is about 88.4098905145.

The spelling of 691039 in words is "six hundred ninety-one thousand, thirty-nine".