256979765 has 12 divisors (see below), whose sum is σ = 358723116. Its totient is φ = 176214528.

The previous prime is 256979761. The next prime is 256979777. The reversal of 256979765 is 567979652.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 177449041 + 79530724 = 13321^2 + 8918^2 .

It is not a de Polignac number, because 256979765 - 2² = 256979761 is a prime.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256979765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256979761) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 524204 + ... + 524693.

It is an arithmetic number, because the mean of its divisors is an integer number (29893593).

Almost surely, 2^256979765 is an apocalyptic number.

It is an amenable number.

256979765 is a deficient number, since it is larger than the sum of its proper divisors (101743351).

256979765 is a wasteful number, since it uses less digits than its factorization.

256979765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048916 (or 1048909 counting only the distinct ones).

The product of its digits is 7144200, while the sum is 56.

The square root of 256979765 is about 16030.5884171480. The cubic root of 256979765 is about 635.7694312422.

The spelling of 256979765 in words is "two hundred fifty-six million, nine hundred seventy-nine thousand, seven hundred sixty-five".