689655240 has 96 divisors (see below), whose sum is σ = 2250963000. Its totient is φ = 183121920.

The previous prime is 689655229. The next prime is 689655257. The reversal of 689655240 is 42556986.

689655240 is a `hidden beast` number, since 6 + 8 + 96 + 552 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 611968644 + 77686596 = 24738^2 + 8814^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82786 + ... + 90734.

Almost surely, 2^689655240 is an apocalyptic number.

689655240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 689655240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1125481500).

689655240 is an abundant number, since it is smaller than the sum of its proper divisors (1561307760).

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

689655240 is a wasteful number, since it uses less digits than its factorization.

689655240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8207 (or 8200 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The square root of 689655240 is about 26261.2878587475. The cubic root of 689655240 is about 883.5083942425.

The spelling of 689655240 in words is "six hundred eighty-nine million, six hundred fifty-five thousand, two hundred forty".