256497720 has 192 divisors, whose sum is σ = 842711040. Its totient is φ = 62380800.

The previous prime is 256497677. The next prime is 256497737. The reversal of 256497720 is 27794652.

256497720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1342825 + ... + 1343015.

It is an arithmetic number, because the mean of its divisors is an integer number (4389120).

Almost surely, 2^256497720 is an apocalyptic number.

256497720 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 256497720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (421355520).

256497720 is an abundant number, since it is smaller than the sum of its proper divisors (586213320).

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

256497720 is a wasteful number, since it uses less digits than its factorization.

256497720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 42.

The square root of 256497720 is about 16015.5461973671. The cubic root of 256497720 is about 635.3716550444.

The spelling of 256497720 in words is "two hundred fifty-six million, four hundred ninety-seven thousand, seven hundred twenty".