65521520 has 40 divisors (see below), whose sum is σ = 152810160. Its totient is φ = 26127360.

The previous prime is 65521517. The next prime is 65521523. The reversal of 65521520 is 2512556.

It is an interprime number because it is at equal distance from previous prime (65521517) and next prime (65521523).

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×65521520³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 65521520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65521523) 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, 29240 + ... + 31400.

It is an arithmetic number, because the mean of its divisors is an integer number (3820254).

Almost surely, 2^65521520 is an apocalyptic number.

It is an amenable number.

65521520 is an abundant number, since it is smaller than the sum of its proper divisors (87288640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65521520 is a wasteful number, since it uses less digits than its factorization.

65521520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2553 (or 2547 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 65521520 is about 8094.5364289748. The cubic root of 65521520 is about 403.1450403274.

The spelling of 65521520 in words is "sixty-five million, five hundred twenty-one thousand, five hundred twenty".