65415581 has 16 divisors (see below), whose sum is σ = 81744768. Its totient is φ = 50856000.

The previous prime is 65415569. The next prime is 65415583. The reversal of 65415581 is 18551456.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 65415581 - 2¹⁸ = 65153437 is a prime.

It is a super-2 number, since 2×65415581² = 8558396475135122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65415583) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49631 + ... + 50931.

It is an arithmetic number, because the mean of its divisors is an integer number (5109048).

Almost surely, 2^65415581 is an apocalyptic number.

It is an amenable number.

65415581 is a deficient number, since it is larger than the sum of its proper divisors (16329187).

65415581 is a wasteful number, since it uses less digits than its factorization.

65415581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1972.

The product of its digits is 24000, while the sum is 35.

The square root of 65415581 is about 8087.9899233369. The cubic root of 65415581 is about 402.9276470132.

The spelling of 65415581 in words is "sixty-five million, four hundred fifteen thousand, five hundred eighty-one".