650128681 has 16 divisors (see below), whose sum is σ = 691004160. Its totient is φ = 609955920.

The previous prime is 650128673. The next prime is 650128691. The reversal of 650128681 is 186821056.

It is a cyclic number.

It is not a de Polignac number, because 650128681 - 2³ = 650128673 is a prime.

It is a super-2 number, since 2×650128681² = 845334603717599522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 650128681.

It is not an unprimeable number, because it can be changed into a prime (650128691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1323846 + ... + 1324336.

It is an arithmetic number, because the mean of its divisors is an integer number (43187760).

Almost surely, 2^650128681 is an apocalyptic number.

It is an amenable number.

650128681 is a deficient number, since it is larger than the sum of its proper divisors (40875479).

650128681 is a wasteful number, since it uses less digits than its factorization.

650128681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 650128681 is about 25497.6210851130. The cubic root of 650128681 is about 866.2962649098.

The spelling of 650128681 in words is "six hundred fifty million, one hundred twenty-eight thousand, six hundred eighty-one".