65655561 has 4 divisors (see below), whose sum is σ = 87540752. Its totient is φ = 43770372.

The previous prime is 65655559. The next prime is 65655563. The reversal of 65655561 is 16555656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (65655559) and next prime (65655563).

It is not a de Polignac number, because 65655561 - 2¹ = 65655559 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65655563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10942591 + ... + 10942596.

It is an arithmetic number, because the mean of its divisors is an integer number (21885188).

Almost surely, 2^65655561 is an apocalyptic number.

It is an amenable number.

65655561 is a deficient number, since it is larger than the sum of its proper divisors (21885191).

65655561 is a wasteful number, since it uses less digits than its factorization.

65655561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21885190.

The product of its digits is 135000, while the sum is 39.

The square root of 65655561 is about 8102.8119193278. The cubic root of 65655561 is about 403.4197651134.

The spelling of 65655561 in words is "sixty-five million, six hundred fifty-five thousand, five hundred sixty-one".