65188661 has 4 divisors (see below), whose sum is σ = 65497824. Its totient is φ = 64879500.

The previous prime is 65188633. The next prime is 65188681. The reversal of 65188661 is 16688156.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 65188661 - 2¹⁴ = 65172277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65188631) 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, 154265 + ... + 154686.

It is an arithmetic number, because the mean of its divisors is an integer number (16374456).

Almost surely, 2^65188661 is an apocalyptic number.

It is an amenable number.

65188661 is a deficient number, since it is larger than the sum of its proper divisors (309163).

65188661 is a wasteful number, since it uses less digits than its factorization.

65188661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309162.

The product of its digits is 69120, while the sum is 41.

The square root of 65188661 is about 8073.9495291957. The cubic root of 65188661 is about 402.4612022323.

The spelling of 65188661 in words is "sixty-five million, one hundred eighty-eight thousand, six hundred sixty-one".