691253 has 4 divisors (see below), whose sum is σ = 693420. Its totient is φ = 689088.

The previous prime is 691241. The next prime is 691267. The reversal of 691253 is 352196.

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

It can be written as a sum of positive squares in 2 ways, for example, as 253009 + 438244 = 503^2 + 662^2 .

It is a cyclic number.

It is not a de Polignac number, because 691253 - 2⁶ = 691189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691153) 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, 500 + ... + 1277.

It is an arithmetic number, because the mean of its divisors is an integer number (173355).

2⁶⁹¹²⁵³ is an apocalyptic number.

It is an amenable number.

691253 is a deficient number, since it is larger than the sum of its proper divisors (2167).

691253 is a wasteful number, since it uses less digits than its factorization.

691253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2166.

The product of its digits is 1620, while the sum is 26.

The square root of 691253 is about 831.4162615682. The cubic root of 691253 is about 88.4190157900.

The spelling of 691253 in words is "six hundred ninety-one thousand, two hundred fifty-three".