256021501 has 4 divisors (see below), whose sum is σ = 258287292. Its totient is φ = 253755712.

The previous prime is 256021499. The next prime is 256021511. The reversal of 256021501 is 105120652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2893401 + 253128100 = 1701^2 + 15910^2 .

It is a cyclic number.

It is not a de Polignac number, because 256021501 - 2¹ = 256021499 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256021511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1132726 + ... + 1132951.

It is an arithmetic number, because the mean of its divisors is an integer number (64571823).

Almost surely, 2^256021501 is an apocalyptic number.

It is an amenable number.

256021501 is a deficient number, since it is larger than the sum of its proper divisors (2265791).

256021501 is a wasteful number, since it uses less digits than its factorization.

256021501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2265790.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 256021501 is about 16000.6718921425. The cubic root of 256021501 is about 634.9781967011.

The spelling of 256021501 in words is "two hundred fifty-six million, twenty-one thousand, five hundred one".