65471721 has 32 divisors (see below), whose sum is σ = 103784448. Its totient is φ = 35925120.

The previous prime is 65471719. The next prime is 65471723. The reversal of 65471721 is 12717456.

It is an interprime number because it is at equal distance from previous prime (65471719) and next prime (65471723).

It is not a de Polignac number, because 65471721 - 2¹ = 65471719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65471723) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 105805 + ... + 106421.

It is an arithmetic number, because the mean of its divisors is an integer number (3243264).

Almost surely, 2^65471721 is an apocalyptic number.

It is an amenable number.

65471721 is a deficient number, since it is larger than the sum of its proper divisors (38312727).

65471721 is a wasteful number, since it uses less digits than its factorization.

65471721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821.

The product of its digits is 11760, while the sum is 33.

The square root of 65471721 is about 8091.4597570525. The cubic root of 65471721 is about 403.0428789395.

The spelling of 65471721 in words is "sixty-five million, four hundred seventy-one thousand, seven hundred twenty-one".