690551 has 4 divisors (see below), whose sum is σ = 698400. Its totient is φ = 682704.

The previous prime is 690541. The next prime is 690553. The reversal of 690551 is 155096.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-690551 is a prime.

It is a Duffinian number.

It is a plaindrome in base 6.

It is a zygodrome in base 6.

It is a self number, because there is not a number n which added to its sum of digits gives 690551.

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 690551.

It is not an unprimeable number, because it can be changed into a prime (690553) 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, 3791 + ... + 3968.

It is an arithmetic number, because the mean of its divisors is an integer number (174600).

2⁶⁹⁰⁵⁵¹ is an apocalyptic number.

690551 is a deficient number, since it is larger than the sum of its proper divisors (7849).

690551 is an equidigital number, since it uses as much as digits as its factorization.

690551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7848.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 690551 is about 830.9939831310. The cubic root of 690551 is about 88.3890744262.

The spelling of 690551 in words is "six hundred ninety thousand, five hundred fifty-one".