65172281 has 4 divisors (see below), whose sum is σ = 66933732. Its totient is φ = 63410832.

The previous prime is 65172277. The next prime is 65172287. The reversal of 65172281 is 18227156.

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 63043600 + 2128681 = 7940^2 + 1459^2 .

It is a cyclic number.

It is not a de Polignac number, because 65172281 - 2² = 65172277 is a prime.

It is a super-2 number, since 2×65172281² = 8494852421485922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65172287) 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, 880670 + ... + 880743.

It is an arithmetic number, because the mean of its divisors is an integer number (16733433).

Almost surely, 2^65172281 is an apocalyptic number.

It is an amenable number.

65172281 is a deficient number, since it is larger than the sum of its proper divisors (1761451).

65172281 is a wasteful number, since it uses less digits than its factorization.

65172281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1761450.

The product of its digits is 6720, while the sum is 32.

The square root of 65172281 is about 8072.9350920220. The cubic root of 65172281 is about 402.4274905069.

The spelling of 65172281 in words is "sixty-five million, one hundred seventy-two thousand, two hundred eighty-one".