65381721 has 8 divisors (see below), whose sum is σ = 87384384. Its totient is φ = 43483440.

The previous prime is 65381713. The next prime is 65381737. The reversal of 65381721 is 12718356.

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

It is not a de Polignac number, because 65381721 - 2³ = 65381713 is a prime.

It is a super-3 number, since 3×65381721³ (a number of 24 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (65381761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24621 + ... + 27146.

It is an arithmetic number, because the mean of its divisors is an integer number (10923048).

Almost surely, 2^65381721 is an apocalyptic number.

It is an amenable number.

65381721 is a deficient number, since it is larger than the sum of its proper divisors (22002663).

65381721 is a wasteful number, since it uses less digits than its factorization.

65381721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52191.

The product of its digits is 10080, while the sum is 33.

The square root of 65381721 is about 8085.8964252580. The cubic root of 65381721 is about 402.8581147267.

The spelling of 65381721 in words is "sixty-five million, three hundred eighty-one thousand, seven hundred twenty-one".