65721113 has 4 divisors (see below), whose sum is σ = 66961188. Its totient is φ = 64481040.

The previous prime is 65721101. The next prime is 65721119. The reversal of 65721113 is 31112756.

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 57638464 + 8082649 = 7592^2 + 2843^2 .

It is a cyclic number.

It is not a de Polignac number, because 65721113 - 2⁶ = 65721049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65721119) 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, 619958 + ... + 620063.

It is an arithmetic number, because the mean of its divisors is an integer number (16740297).

Almost surely, 2^65721113 is an apocalyptic number.

It is an amenable number.

65721113 is a deficient number, since it is larger than the sum of its proper divisors (1240075).

65721113 is a wasteful number, since it uses less digits than its factorization.

65721113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1240074.

The product of its digits is 1260, while the sum is 26.

The square root of 65721113 is about 8106.8559256965. The cubic root of 65721113 is about 403.5539816003.

Adding to 65721113 its reverse (31112756), we get a palindrome (96833869).

The spelling of 65721113 in words is "sixty-five million, seven hundred twenty-one thousand, one hundred thirteen".