1256216328 has 24 divisors (see below), whose sum is σ = 3402252750. Its totient is φ = 418738752.

The previous prime is 1256216321. The next prime is 1256216333. The reversal of 1256216328 is 8236126521.

1256216328 is a `hidden beast` number, since 1 + 2 + 5 + 621 + 6 + 3 + 28 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1079911044 + 176305284 = 32862^2 + 13278^2 .

It is a tau number, because it is divible by the number of its divisors (24).

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 = 1256216292 and 1256216301.

It is not an unprimeable number, because it can be changed into a prime (1256216321) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8723653 + ... + 8723796.

Almost surely, 2^1256216328 is an apocalyptic number.

1256216328 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1256216328 is an abundant number, since it is smaller than the sum of its proper divisors (2146036422).

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

1256216328 is a wasteful number, since it uses less digits than its factorization.

1256216328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17447461 (or 17447454 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1256216328 is about 35443.1421857600. The cubic root of 1256216328 is about 1079.0000827435. Note that the first 4 decimals are identical.

The spelling of 1256216328 in words is "one billion, two hundred fifty-six million, two hundred sixteen thousand, three hundred twenty-eight".