65643939 has 10 divisors (see below), whose sum is σ = 98060820. Its totient is φ = 43762572.

The previous prime is 65643923. The next prime is 65643943. The reversal of 65643939 is 93934656.

It is a happy number.

It is not a de Polignac number, because 65643939 - 2⁴ = 65643923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 65643894 and 65643903.

It is not an unprimeable number, because it can be changed into a prime (65643989) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 405129 + ... + 405290.

It is an arithmetic number, because the mean of its divisors is an integer number (9806082).

Almost surely, 2^65643939 is an apocalyptic number.

65643939 is a deficient number, since it is larger than the sum of its proper divisors (32416881).

65643939 is an equidigital number, since it uses as much as digits as its factorization.

65643939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810431 (or 810422 counting only the distinct ones).

The product of its digits is 524880, while the sum is 45.

The square root of 65643939 is about 8102.0947291426. The cubic root of 65643939 is about 403.3959599647.

The spelling of 65643939 in words is "sixty-five million, six hundred forty-three thousand, nine hundred thirty-nine".