259906021 has 2 divisors, whose sum is σ = 259906022. Its totient is φ = 259906020.

The previous prime is 259906007. The next prime is 259906037. The reversal of 259906021 is 120609952.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 259660996 + 245025 = 16114^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 259906021 - 2⁹ = 259905509 is a prime.

It is a super-2 number, since 2×259906021² = 135102279504104882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (259906001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129953010 + 129953011.

It is an arithmetic number, because the mean of its divisors is an integer number (129953011).

Almost surely, 2^259906021 is an apocalyptic number.

It is an amenable number.

259906021 is a deficient number, since it is larger than the sum of its proper divisors (1).

259906021 is an equidigital number, since it uses as much as digits as its factorization.

259906021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 259906021 is about 16121.6010681322. The cubic root of 259906021 is about 638.1735204429.

The spelling of 259906021 in words is "two hundred fifty-nine million, nine hundred six thousand, twenty-one".