65665581437 has 4 divisors (see below), whose sum is σ = 69528262716. Its totient is φ = 61802900160.

The previous prime is 65665581433. The next prime is 65665581467. The reversal of 65665581437 is 73418556656.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 48370964356 + 17294617081 = 219934^2 + 131509^2 .

It is a cyclic number.

It is not a de Polignac number, because 65665581437 - 2² = 65665581433 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 (65665581433) 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, 1931340614 + ... + 1931340647.

It is an arithmetic number, because the mean of its divisors is an integer number (17382065679).

Almost surely, 2^65665581437 is an apocalyptic number.

It is an amenable number.

65665581437 is a deficient number, since it is larger than the sum of its proper divisors (3862681279).

65665581437 is a wasteful number, since it uses less digits than its factorization.

65665581437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3862681278.

The product of its digits is 18144000, while the sum is 56.

The spelling of 65665581437 in words is "sixty-five billion, six hundred sixty-five million, five hundred eighty-one thousand, four hundred thirty-seven".