20258261 has 2 divisors, whose sum is σ = 20258262. Its totient is φ = 20258260.

The previous prime is 20258213. The next prime is 20258263. The reversal of 20258261 is 16285202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13912900 + 6345361 = 3730^2 + 2519^2 .

It is a cyclic number.

It is not a de Polignac number, because 20258261 - 2¹⁴ = 20241877 is a prime.

Together with 20258263, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20258261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20258263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10129130 + 10129131.

It is an arithmetic number, because the mean of its divisors is an integer number (10129131).

Almost surely, 2^20258261 is an apocalyptic number.

It is an amenable number.

20258261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20258261 is an equidigital number, since it uses as much as digits as its factorization.

20258261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 20258261 is about 4500.9177952946. The cubic root of 20258261 is about 272.6051486591.

The spelling of 20258261 in words is "twenty million, two hundred fifty-eight thousand, two hundred sixty-one".