65121779 has 2 divisors, whose sum is σ = 65121780. Its totient is φ = 65121778.

The previous prime is 65121773. The next prime is 65121799. The reversal of 65121779 is 97712156.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 65121779 - 2²⁴ = 48344563 is a prime.

It is a super-2 number, since 2×65121779² = 8481692200249682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (65121773) 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, 32560889 + 32560890.

It is an arithmetic number, because the mean of its divisors is an integer number (32560890).

Almost surely, 2^65121779 is an apocalyptic number.

65121779 is a deficient number, since it is larger than the sum of its proper divisors (1).

65121779 is an equidigital number, since it uses as much as digits as its factorization.

65121779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26460, while the sum is 38.

The square root of 65121779 is about 8069.8066271752. The cubic root of 65121779 is about 402.3235166261.

The spelling of 65121779 in words is "sixty-five million, one hundred twenty-one thousand, seven hundred seventy-nine".