65531540 has 24 divisors (see below), whose sum is σ = 137852232. Its totient is φ = 26167680.

The previous prime is 65531537. The next prime is 65531567. The reversal of 65531540 is 4513556.

It can be written as a sum of positive squares in 4 ways, for example, as 25361296 + 40170244 = 5036^2 + 6338^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10742 + ... + 15698.

It is an arithmetic number, because the mean of its divisors is an integer number (5743843).

Almost surely, 2^65531540 is an apocalyptic number.

It is an amenable number.

65531540 is an abundant number, since it is smaller than the sum of its proper divisors (72320692).

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

65531540 is a wasteful number, since it uses less digits than its factorization.

65531540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5627 (or 5625 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 29.

The square root of 65531540 is about 8095.1553413137. The cubic root of 65531540 is about 403.1655898476.

The spelling of 65531540 in words is "sixty-five million, five hundred thirty-one thousand, five hundred forty".