65616621 has 16 divisors (see below), whose sum is σ = 100176384. Its totient is φ = 37424304.

The previous prime is 65616619. The next prime is 65616623. The reversal of 65616621 is 12661656.

It is an interprime number because it is at equal distance from previous prime (65616619) and next prime (65616623).

It is not a de Polignac number, because 65616621 - 2¹ = 65616619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65616623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9666 + ... + 14988.

It is an arithmetic number, because the mean of its divisors is an integer number (6261024).

Almost surely, 2^65616621 is an apocalyptic number.

It is an amenable number.

65616621 is a deficient number, since it is larger than the sum of its proper divisors (34559763).

65616621 is a wasteful number, since it uses less digits than its factorization.

65616621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5920.

The product of its digits is 12960, while the sum is 33.

The square root of 65616621 is about 8100.4086933932. The cubic root of 65616621 is about 403.3399938947.

The spelling of 65616621 in words is "sixty-five million, six hundred sixteen thousand, six hundred twenty-one".