65664251 has 8 divisors (see below), whose sum is σ = 70203744. Its totient is φ = 61200000.

The previous prime is 65664239. The next prime is 65664259. The reversal of 65664251 is 15246656.

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

It is not a de Polignac number, because 65664251 - 2¹⁸ = 65402107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65664259) 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 in 7 ways as a sum of consecutive naturals, for example, 17000 + ... + 20501.

It is an arithmetic number, because the mean of its divisors is an integer number (8775468).

Almost surely, 2^65664251 is an apocalyptic number.

65664251 is a deficient number, since it is larger than the sum of its proper divisors (4539493).

65664251 is a wasteful number, since it uses less digits than its factorization.

65664251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37621.

The product of its digits is 43200, while the sum is 35.

The square root of 65664251 is about 8103.3481351846. The cubic root of 65664251 is about 403.4375628599.

The spelling of 65664251 in words is "sixty-five million, six hundred sixty-four thousand, two hundred fifty-one".