690690 has 128 divisors (see below), whose sum is σ = 2322432. Its totient is φ = 126720.

The previous prime is 690689. The next prime is 690719. The reversal of 690690 is 96096.

It is a super-2 number, since 2×690690² = 954105352200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30019 + ... + 30041.

It is an arithmetic number, because the mean of its divisors is an integer number (18144).

2⁶⁹⁰⁶⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 690690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1161216).

690690 is an abundant number, since it is smaller than the sum of its proper divisors (1631742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

690690 is a wasteful number, since it uses less digits than its factorization.

690690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 690690 is about 831.0776137040. The cubic root of 690690 is about 88.3950045975.

It can be divided in two parts, 6906 and 90, that added together give a palindrome (6996).

The spelling of 690690 in words is "six hundred ninety thousand, six hundred ninety".