690191 has 4 divisors (see below), whose sum is σ = 699984. Its totient is φ = 680400.

The previous prime is 690187. The next prime is 690233. The reversal of 690191 is 191096.

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 690191 - 2² = 690187 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 690191.

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 690191.

It is not an unprimeable number, because it can be changed into a prime (690491) 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, 4790 + ... + 4931.

It is an arithmetic number, because the mean of its divisors is an integer number (174996).

2⁶⁹⁰¹⁹¹ is an apocalyptic number.

690191 is a deficient number, since it is larger than the sum of its proper divisors (9793).

690191 is an equidigital number, since it uses as much as digits as its factorization.

690191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9792.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 690191 is about 830.7773468265. Note that the first 3 decimals coincide. The cubic root of 690191 is about 88.3737120089.

The spelling of 690191 in words is "six hundred ninety thousand, one hundred ninety-one".