65306640 has 80 divisors (see below), whose sum is σ = 231378048. Its totient is φ = 14926848.

The previous prime is 65306623. The next prime is 65306669. The reversal of 65306640 is 4660356.

65306640 is nontrivially palindromic in base 11.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 65306598 and 65306607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17757 + ... + 21116.

Almost surely, 2^65306640 is an apocalyptic number.

65306640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65306640 is an abundant number, since it is smaller than the sum of its proper divisors (166071408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65306640 is a wasteful number, since it uses less digits than its factorization.

65306640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38896 (or 38890 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 65306640 is about 8081.2523781899. The cubic root of 65306640 is about 402.7038484931.

Adding to 65306640 its reverse (4660356), we get a palindrome (69966996).

The spelling of 65306640 in words is "sixty-five million, three hundred six thousand, six hundred forty".