65878261 has 2 divisors, whose sum is σ = 65878262. Its totient is φ = 65878260.

The previous prime is 65878259. The next prime is 65878271. The reversal of 65878261 is 16287856.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64096036 + 1782225 = 8006^2 + 1335^2 .

It is a cyclic number.

It is not a de Polignac number, because 65878261 - 2¹ = 65878259 is a prime.

Together with 65878259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65878271) 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 as a sum of consecutive naturals, namely, 32939130 + 32939131.

It is an arithmetic number, because the mean of its divisors is an integer number (32939131).

Almost surely, 2^65878261 is an apocalyptic number.

It is an amenable number.

65878261 is a deficient number, since it is larger than the sum of its proper divisors (1).

65878261 is an equidigital number, since it uses as much as digits as its factorization.

65878261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 161280, while the sum is 43.

The square root of 65878261 is about 8116.5424288918. The cubic root of 65878261 is about 403.8753761442.

The spelling of 65878261 in words is "sixty-five million, eight hundred seventy-eight thousand, two hundred sixty-one".