65016721 has 16 divisors (see below), whose sum is σ = 85829760. Its totient is φ = 47681280.

The previous prime is 65016719. The next prime is 65016737. The reversal of 65016721 is 12761056.

It is a cyclic number.

It is not a de Polignac number, because 65016721 - 2¹ = 65016719 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65016721.

It is not an unprimeable number, because it can be changed into a prime (65016701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23526 + ... + 26143.

It is an arithmetic number, because the mean of its divisors is an integer number (5364360).

Almost surely, 2^65016721 is an apocalyptic number.

It is an amenable number.

65016721 is a deficient number, since it is larger than the sum of its proper divisors (20813039).

65016721 is a wasteful number, since it uses less digits than its factorization.

65016721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49704.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 65016721 is about 8063.2946740151. The cubic root of 65016721 is about 402.1070501109.

Adding to 65016721 its reverse (12761056), we get a palindrome (77777777).

It can be divided in two parts, 650 and 16721, that added together give a palindrome (17371).

The spelling of 65016721 in words is "sixty-five million, sixteen thousand, seven hundred twenty-one".