65399685121 has 2 divisors, whose sum is σ = 65399685122. Its totient is φ = 65399685120.

The previous prime is 65399685103. The next prime is 65399685139. The reversal of 65399685121 is 12158699356.

It is a balanced prime because it is at equal distance from previous prime (65399685103) and next prime (65399685139).

It can be written as a sum of positive squares in only one way, i.e., 62468004096 + 2931681025 = 249936^2 + 54145^2 .

It is a cyclic number.

It is not a de Polignac number, because 65399685121 - 2²⁵ = 65366130689 is a prime.

It is not a weakly prime, because it can be changed into another prime (65399685191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32699842560 + 32699842561.

It is an arithmetic number, because the mean of its divisors is an integer number (32699842561).

It is a Proth number, since it is equal to 31185 ⋅ 2²¹ + 1 and 31185 < 2²¹.

Almost surely, 2^65399685121 is an apocalyptic number.

It is an amenable number.

65399685121 is a deficient number, since it is larger than the sum of its proper divisors (1).

65399685121 is an equidigital number, since it uses as much as digits as its factorization.

65399685121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3499200, while the sum is 55.

The spelling of 65399685121 in words is "sixty-five billion, three hundred ninety-nine million, six hundred eighty-five thousand, one hundred twenty-one".