258506640 has 400 divisors, whose sum is σ = 1058682240. Its totient is φ = 57231360.

The previous prime is 258506639. The next prime is 258506653. The reversal of 258506640 is 46605852.

258506640 is a `hidden beast` number, since 2 + 5 + 8 + 5 + 0 + 6 + 640 = 666.

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 = 258506595 and 258506604.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1859691 + ... + 1859829.

Almost surely, 2^258506640 is an apocalyptic number.

258506640 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 258506640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (529341120).

258506640 is an abundant number, since it is smaller than the sum of its proper divisors (800175600).

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

258506640 is a wasteful number, since it uses less digits than its factorization.

258506640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 258506640 is about 16078.1416836648. The cubic root of 258506640 is about 637.0261114879.

The spelling of 258506640 in words is "two hundred fifty-eight million, five hundred six thousand, six hundred forty".