65721042 has 12 divisors (see below), whose sum is σ = 142395630. Its totient is φ = 21907008.

The previous prime is 65721001. The next prime is 65721049. The reversal of 65721042 is 24012756.

65721042 is a `hidden beast` number, since 657 + 2 + 1 + 0 + 4 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 64979721 + 741321 = 8061^2 + 861^2 .

It is a junction number, because it is equal to n+sod(n) for n = 65720997 and 65721015.

It is not an unprimeable number, because it can be changed into a prime (65721049) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1825567 + ... + 1825602.

Almost surely, 2^65721042 is an apocalyptic number.

65721042 is an abundant number, since it is smaller than the sum of its proper divisors (76674588).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65721042 is a wasteful number, since it uses less digits than its factorization.

65721042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3651177 (or 3651174 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 65721042 is about 8106.8515466857. The cubic root of 65721042 is about 403.5538362775.

Adding to 65721042 its reverse (24012756), we get a palindrome (89733798).

The spelling of 65721042 in words is "sixty-five million, seven hundred twenty-one thousand, forty-two".