685609280 has 28 divisors (see below), whose sum is σ = 1632607860. Its totient is φ = 274243584.

The previous prime is 685609247. The next prime is 685609291. The reversal of 685609280 is 82906586.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 473149504 + 212459776 = 21752^2 + 14576^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1070945 + ... + 1071584.

Almost surely, 2^685609280 is an apocalyptic number.

It is an amenable number.

685609280 is an abundant number, since it is smaller than the sum of its proper divisors (946998580).

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

685609280 is a wasteful number, since it uses less digits than its factorization.

685609280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2142546 (or 2142536 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 44.

The square root of 685609280 is about 26184.1417655802. The cubic root of 685609280 is about 881.7772621907. Note that the first 3 decimals are identical.

The spelling of 685609280 in words is "six hundred eighty-five million, six hundred nine thousand, two hundred eighty".