65221161 has 4 divisors (see below), whose sum is σ = 86961552. Its totient is φ = 43480772.

The previous prime is 65221157. The next prime is 65221171. The reversal of 65221161 is 16112256.

65221161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a cyclic number.

It is not a de Polignac number, because 65221161 - 2² = 65221157 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65221171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10870191 + ... + 10870196.

It is an arithmetic number, because the mean of its divisors is an integer number (21740388).

Almost surely, 2^65221161 is an apocalyptic number.

It is an amenable number.

65221161 is a deficient number, since it is larger than the sum of its proper divisors (21740391).

65221161 is a wasteful number, since it uses less digits than its factorization.

65221161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21740390.

The product of its digits is 720, while the sum is 24.

The square root of 65221161 is about 8075.9619241302. The cubic root of 65221161 is about 402.5280738620.

The spelling of 65221161 in words is "sixty-five million, two hundred twenty-one thousand, one hundred sixty-one".