256420770 has 64 divisors (see below), whose sum is σ = 650160000. Its totient is φ = 64544256.

The previous prime is 256420763. The next prime is 256420771. The reversal of 256420770 is 77024652.

256420770 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×256420770² = 131503222574785800, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (256420771) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 198286 + ... + 199574.

It is an arithmetic number, because the mean of its divisors is an integer number (10158750).

Almost surely, 2^256420770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256420770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (325080000).

256420770 is an abundant number, since it is smaller than the sum of its proper divisors (393739230).

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

256420770 is a wasteful number, since it uses less digits than its factorization.

256420770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667.

The product of its (nonzero) digits is 23520, while the sum is 33.

The square root of 256420770 is about 16013.1436638781. The cubic root of 256420770 is about 635.3081109592.

The spelling of 256420770 in words is "two hundred fifty-six million, four hundred twenty thousand, seven hundred seventy".