65640871 has 8 divisors (see below), whose sum is σ = 67275360. Its totient is φ = 64021152.

The previous prime is 65640851. The next prime is 65640881. The reversal of 65640871 is 17804656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65640871 - 2¹⁷ = 65509799 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65640871.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65640821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5590 + ... + 12748.

It is an arithmetic number, because the mean of its divisors is an integer number (8409420).

Almost surely, 2^65640871 is an apocalyptic number.

65640871 is a deficient number, since it is larger than the sum of its proper divisors (1634489).

65640871 is a wasteful number, since it uses less digits than its factorization.

65640871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7385.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 65640871 is about 8101.9053931776. The cubic root of 65640871 is about 403.3896753627.

The spelling of 65640871 in words is "sixty-five million, six hundred forty thousand, eight hundred seventy-one".