65229721 has 4 divisors (see below), whose sum is σ = 65355444. Its totient is φ = 65104000.

The previous prime is 65229719. The next prime is 65229727. The reversal of 65229721 is 12792256.

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 22458121 + 42771600 = 4739^2 + 6540^2 .

It is a cyclic number.

It is not a de Polignac number, because 65229721 - 2¹ = 65229719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65229727) 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, 62080 + ... + 63121.

It is an arithmetic number, because the mean of its divisors is an integer number (16338861).

Almost surely, 2^65229721 is an apocalyptic number.

It is an amenable number.

65229721 is a deficient number, since it is larger than the sum of its proper divisors (125723).

65229721 is a wasteful number, since it uses less digits than its factorization.

65229721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125722.

The product of its digits is 15120, while the sum is 34.

The square root of 65229721 is about 8076.4918745703. The cubic root of 65229721 is about 402.5456831242.

The spelling of 65229721 in words is "sixty-five million, two hundred twenty-nine thousand, seven hundred twenty-one".