256660740 has 288 divisors, whose sum is σ = 956067840. Its totient is φ = 54432000.

The previous prime is 256660717. The next prime is 256660741. The reversal of 256660740 is 47066652.

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 = 256660695 and 256660704.

It is not an unprimeable number, because it can be changed into a prime (256660741) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1699665 + ... + 1699815.

It is an arithmetic number, because the mean of its divisors is an integer number (3319680).

Almost surely, 2^256660740 is an apocalyptic number.

256660740 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 256660740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (478033920).

256660740 is an abundant number, since it is smaller than the sum of its proper divisors (699407100).

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

256660740 is a wasteful number, since it uses less digits than its factorization.

256660740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 256660740 is about 16020.6348188828. The cubic root of 256660740 is about 635.5062323959.

The spelling of 256660740 in words is "two hundred fifty-six million, six hundred sixty thousand, seven hundred forty".