690785 has 4 divisors (see below), whose sum is σ = 828948. Its totient is φ = 552624.

The previous prime is 690757. The next prime is 690787. The reversal of 690785 is 587096.

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 160801 + 529984 = 401^2 + 728^2 .

It is a cyclic number.

It is not a de Polignac number, because 690785 - 2⁶ = 690721 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690787) 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, 69074 + ... + 69083.

It is an arithmetic number, because the mean of its divisors is an integer number (207237).

2⁶⁹⁰⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

690785 is a deficient number, since it is larger than the sum of its proper divisors (138163).

690785 is a wasteful number, since it uses less digits than its factorization.

690785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138162.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 690785 is about 831.1347664489. The cubic root of 690785 is about 88.3990571346.

The spelling of 690785 in words is "six hundred ninety thousand, seven hundred eighty-five".