65755821 has 4 divisors (see below), whose sum is σ = 87674432. Its totient is φ = 43837212.

The previous prime is 65755801. The next prime is 65755861. The reversal of 65755821 is 12855756.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 65755821 - 2¹⁷ = 65624749 is a prime.

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 65755821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65755801) 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 3 ways as a sum of consecutive naturals, for example, 10959301 + ... + 10959306.

It is an arithmetic number, because the mean of its divisors is an integer number (21918608).

Almost surely, 2^65755821 is an apocalyptic number.

It is an amenable number.

65755821 is a deficient number, since it is larger than the sum of its proper divisors (21918611).

65755821 is a wasteful number, since it uses less digits than its factorization.

65755821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21918610.

The product of its digits is 84000, while the sum is 39.

The square root of 65755821 is about 8108.9963004061. The cubic root of 65755821 is about 403.6250094431.

The spelling of 65755821 in words is "sixty-five million, seven hundred fifty-five thousand, eight hundred twenty-one".