65128820 has 12 divisors (see below), whose sum is σ = 136770564. Its totient is φ = 26051520.

The previous prime is 65128813. The next prime is 65128837. The reversal of 65128820 is 2882156.

It can be written as a sum of positive squares in 2 ways, for example, as 50779876 + 14348944 = 7126^2 + 3788^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1628201 + ... + 1628240.

It is an arithmetic number, because the mean of its divisors is an integer number (11397547).

Almost surely, 2^65128820 is an apocalyptic number.

It is an amenable number.

65128820 is an abundant number, since it is smaller than the sum of its proper divisors (71641744).

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

65128820 is a wasteful number, since it uses less digits than its factorization.

65128820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3256450 (or 3256448 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 65128820 is about 8070.2428711904. The cubic root of 65128820 is about 402.3380159116.

The spelling of 65128820 in words is "sixty-five million, one hundred twenty-eight thousand, eight hundred twenty".