65680821 has 16 divisors (see below), whose sum is σ = 97456320. Its totient is φ = 43719120.

The previous prime is 65680819. The next prime is 65680829. The reversal of 65680821 is 12808656.

It is a happy number.

It is not a de Polignac number, because 65680821 - 2¹ = 65680819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65680829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20686 + ... + 23648.

It is an arithmetic number, because the mean of its divisors is an integer number (6091020).

Almost surely, 2^65680821 is an apocalyptic number.

It is an amenable number.

65680821 is a deficient number, since it is larger than the sum of its proper divisors (31775499).

65680821 is a wasteful number, since it uses less digits than its factorization.

65680821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3793 (or 3787 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 65680821 is about 8104.3704875826. The cubic root of 65680821 is about 403.4714950635.

The spelling of 65680821 in words is "sixty-five million, six hundred eighty thousand, eight hundred twenty-one".