268478640 has 120 divisors (see below), whose sum is σ = 905531328. Its totient is φ = 71285760.

The previous prime is 268478611. The next prime is 268478647. The reversal of 268478640 is 46874862.

It is a tau number, because it is divible by the number of its divisors (120).

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 (268478647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 201657 + ... + 202983.

Almost surely, 2^268478640 is an apocalyptic number.

268478640 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 268478640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (452765664).

268478640 is an abundant number, since it is smaller than the sum of its proper divisors (637052688).

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

268478640 is a wasteful number, since it uses less digits than its factorization.

268478640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627 (or 1618 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The square root of 268478640 is about 16385.3178180956. The cubic root of 268478640 is about 645.1141676400.

The spelling of 268478640 in words is "two hundred sixty-eight million, four hundred seventy-eight thousand, six hundred forty".