65428709 has 4 divisors (see below), whose sum is σ = 66076620. Its totient is φ = 64780800.

The previous prime is 65428703. The next prime is 65428771. The reversal of 65428709 is 90782456.

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 49308484 + 16120225 = 7022^2 + 4015^2 .

It is a cyclic number.

It is not a de Polignac number, because 65428709 - 2⁸ = 65428453 is a prime.

It is a super-2 number, since 2×65428709² = 8561831922813362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65428703) 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, 323804 + ... + 324005.

It is an arithmetic number, because the mean of its divisors is an integer number (16519155).

Almost surely, 2^65428709 is an apocalyptic number.

It is an amenable number.

65428709 is a deficient number, since it is larger than the sum of its proper divisors (647911).

65428709 is a wasteful number, since it uses less digits than its factorization.

65428709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647910.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 65428709 is about 8088.8014563346. The cubic root of 65428709 is about 402.9545992075.

It can be divided in two parts, 6542 and 8709, that added together give a palindrome (15251).

The spelling of 65428709 in words is "sixty-five million, four hundred twenty-eight thousand, seven hundred nine".