65778619 has 2 divisors, whose sum is σ = 65778620. Its totient is φ = 65778618.

The previous prime is 65778613. The next prime is 65778659. The reversal of 65778619 is 91687756.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 65778619 - 2³ = 65778611 is a prime.

It is a super-2 number, since 2×65778619² = 8653653435094322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (65778611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32889309 + 32889310.

It is an arithmetic number, because the mean of its divisors is an integer number (32889310).

Almost surely, 2^65778619 is an apocalyptic number.

65778619 is a deficient number, since it is larger than the sum of its proper divisors (1).

65778619 is an equidigital number, since it uses as much as digits as its factorization.

65778619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 635040, while the sum is 49.

The square root of 65778619 is about 8110.4019012624. The cubic root of 65778619 is about 403.6716505850.

The spelling of 65778619 in words is "sixty-five million, seven hundred seventy-eight thousand, six hundred nineteen".