256180561920 has 768 divisors, whose sum is σ = 955281600000. Its totient is φ = 65036353536.

The previous prime is 256180561919. The next prime is 256180561921. The reversal of 256180561920 is 29165081652.

256180561920 is a `hidden beast` number, since 2 + 5 + 6 + 1 + 8 + 0 + 5 + 619 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (256180561919) and next prime (256180561921).

It is a tau number, because it is divible by the number of its divisors (768).

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 (256180561921) 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, 713594701 + ... + 713595059.

It is an arithmetic number, because the mean of its divisors is an integer number (1243856250).

Almost surely, 2^256180561920 is an apocalyptic number.

256180561920 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 256180561920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (477640800000).

256180561920 is an abundant number, since it is smaller than the sum of its proper divisors (699101038080).

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

256180561920 is a wasteful number, since it uses less digits than its factorization.

256180561920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513 (or 487 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 256180561920 in words is "two hundred fifty-six billion, one hundred eighty million, five hundred sixty-one thousand, nine hundred twenty".