65680021 has 8 divisors (see below), whose sum is σ = 72309600. Its totient is φ = 59160240.

The previous prime is 65679989. The next prime is 65680031. The reversal of 65680021 is 12008656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65680021 - 2⁵ = 65679989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65680031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26191 + ... + 28588.

It is an arithmetic number, because the mean of its divisors is an integer number (9038700).

Almost surely, 2^65680021 is an apocalyptic number.

It is an amenable number.

65680021 is a deficient number, since it is larger than the sum of its proper divisors (6629579).

65680021 is a wasteful number, since it uses less digits than its factorization.

65680021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54899.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 65680021 is about 8104.3211313472. The cubic root of 65680021 is about 403.4698569470.

Adding to 65680021 its reverse (12008656), we get a palindrome (77688677).

It can be divided in two parts, 65 and 680021, that added together give a palindrome (680086).

The spelling of 65680021 in words is "sixty-five million, six hundred eighty thousand, twenty-one".