259521665940 has 216 divisors, whose sum is σ = 819035721504. Its totient is φ = 66480825600.

The previous prime is 259521665891. The next prime is 259521665957. The reversal of 259521665940 is 49566125952.

259521665940 is a `hidden beast` number, since 2 + 5 + 9 + 521 + 66 + 59 + 4 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 28796035 + ... + 28805045.

It is an arithmetic number, because the mean of its divisors is an integer number (3791832044).

Almost surely, 2^259521665940 is an apocalyptic number.

259521665940 is a gapful number since it is divisible by the number (20) 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 259521665940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (409517860752).

259521665940 is an abundant number, since it is smaller than the sum of its proper divisors (559514055564).

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

259521665940 is a wasteful number, since it uses less digits than its factorization.

259521665940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9191 (or 9125 counting only the distinct ones).

The product of its (nonzero) digits is 5832000, while the sum is 54.

The spelling of 259521665940 in words is "two hundred fifty-nine billion, five hundred twenty-one million, six hundred sixty-five thousand, nine hundred forty".