65143921 has 4 divisors (see below), whose sum is σ = 65168100. Its totient is φ = 65119744.

The previous prime is 65143919. The next prime is 65143937. The reversal of 65143921 is 12934156.

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 62583921 + 2560000 = 7911^2 + 1600^2 .

It is a cyclic number.

It is not a de Polignac number, because 65143921 - 2¹ = 65143919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65143621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7456 + ... + 13633.

It is an arithmetic number, because the mean of its divisors is an integer number (16292025).

Almost surely, 2^65143921 is an apocalyptic number.

It is an amenable number.

65143921 is a deficient number, since it is larger than the sum of its proper divisors (24179).

65143921 is a wasteful number, since it uses less digits than its factorization.

65143921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24178.

The product of its digits is 6480, while the sum is 31.

The square root of 65143921 is about 8071.1784145811. The cubic root of 65143921 is about 402.3691093500.

The spelling of 65143921 in words is "sixty-five million, one hundred forty-three thousand, nine hundred twenty-one".