65424721 has 4 divisors (see below), whose sum is σ = 69273252. Its totient is φ = 61576192.

The previous prime is 65424713. The next prime is 65424727. The reversal of 65424721 is 12742456.

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 45711121 + 19713600 = 6761^2 + 4440^2 .

It is a cyclic number.

It is not a de Polignac number, because 65424721 - 2³ = 65424713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65424727) 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, 1924240 + ... + 1924273.

It is an arithmetic number, because the mean of its divisors is an integer number (17318313).

Almost surely, 2^65424721 is an apocalyptic number.

It is an amenable number.

65424721 is a deficient number, since it is larger than the sum of its proper divisors (3848531).

65424721 is a wasteful number, since it uses less digits than its factorization.

65424721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3848530.

The product of its digits is 13440, while the sum is 31.

The square root of 65424721 is about 8088.5549389245. The cubic root of 65424721 is about 402.9464121001.

The spelling of 65424721 in words is "sixty-five million, four hundred twenty-four thousand, seven hundred twenty-one".