2256021709 has 2 divisors, whose sum is σ = 2256021710. Its totient is φ = 2256021708.

The previous prime is 2256021673. The next prime is 2256021727. The reversal of 2256021709 is 9071206522.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1676656809 + 579364900 = 40947^2 + 24070^2 .

It is a cyclic number.

It is not a de Polignac number, because 2256021709 - 2¹⁵ = 2255988941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2256021799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1128010854 + 1128010855.

It is an arithmetic number, because the mean of its divisors is an integer number (1128010855).

Almost surely, 2^2256021709 is an apocalyptic number.

It is an amenable number.

2256021709 is a deficient number, since it is larger than the sum of its proper divisors (1).

2256021709 is an equidigital number, since it uses as much as digits as its factorization.

2256021709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 2256021709 is about 47497.5968760526. The cubic root of 2256021709 is about 1311.5386440912.

The spelling of 2256021709 in words is "two billion, two hundred fifty-six million, twenty-one thousand, seven hundred nine".