65521471 has 4 divisors (see below), whose sum is σ = 65538000. Its totient is φ = 65504944.

The previous prime is 65521429. The next prime is 65521513. The reversal of 65521471 is 17412556.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (65521429) and next prime (65521513).

It is a cyclic number.

It is not a de Polignac number, because 65521471 - 2¹⁹ = 64997183 is a prime.

It is a super-3 number, since 3×65521471³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65521171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1635 + ... + 11563.

It is an arithmetic number, because the mean of its divisors is an integer number (16384500).

Almost surely, 2^65521471 is an apocalyptic number.

65521471 is a deficient number, since it is larger than the sum of its proper divisors (16529).

65521471 is an equidigital number, since it uses as much as digits as its factorization.

65521471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16528.

The product of its digits is 8400, while the sum is 31.

The square root of 65521471 is about 8094.5334022413. The cubic root of 65521471 is about 403.1449398306.

The spelling of 65521471 in words is "sixty-five million, five hundred twenty-one thousand, four hundred seventy-one".