258398640 has 320 divisors, whose sum is σ = 977080320. Its totient is φ = 62484480.

The previous prime is 258398633. The next prime is 258398641. The reversal of 258398640 is 46893852.

258398640 is a `hidden beast` number, since 2 + 583 + 9 + 8 + 64 + 0 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (258398641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1138207 + ... + 1138433.

It is an arithmetic number, because the mean of its divisors is an integer number (3053376).

Almost surely, 2^258398640 is an apocalyptic number.

258398640 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 258398640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488540160).

258398640 is an abundant number, since it is smaller than the sum of its proper divisors (718681680).

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

258398640 is a wasteful number, since it uses less digits than its factorization.

258398640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 258398640 is about 16074.7827357013. The cubic root of 258398640 is about 636.9373859742.

The spelling of 258398640 in words is "two hundred fifty-eight million, three hundred ninety-eight thousand, six hundred forty".