259640640 has 448 divisors, whose sum is σ = 1079723520. Its totient is φ = 58226688.

The previous prime is 259640621. The next prime is 259640663. The reversal of 259640640 is 46046952.

259640640 is a `hidden beast` number, since 2 + 5 + 9 + 6 + 4 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 259640595 and 259640604.

It is a congruent 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, 4898854 + ... + 4898906.

Almost surely, 2^259640640 is an apocalyptic number.

259640640 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 259640640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (539861760).

259640640 is an abundant number, since it is smaller than the sum of its proper divisors (820082880).

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

259640640 is an frugal number, since it uses more digits than its factorization.

259640640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 259640640 is about 16113.3683629463. The cubic root of 259640640 is about 637.9562408774.

The spelling of 259640640 in words is "two hundred fifty-nine million, six hundred forty thousand, six hundred forty".