649828121 has 4 divisors (see below), whose sum is σ = 649893732. Its totient is φ = 649762512.

The previous prime is 649828117. The next prime is 649828141. The reversal of 649828121 is 121828946.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 180499225 + 469328896 = 13435^2 + 21664^2 .

It is a cyclic number.

It is not a de Polignac number, because 649828121 - 2² = 649828117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (649828141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14570 + ... + 38883.

It is an arithmetic number, because the mean of its divisors is an integer number (162473433).

Almost surely, 2^649828121 is an apocalyptic number.

It is an amenable number.

649828121 is a deficient number, since it is larger than the sum of its proper divisors (65611).

649828121 is a wasteful number, since it uses less digits than its factorization.

649828121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65610.

The product of its digits is 55296, while the sum is 41.

The square root of 649828121 is about 25491.7265205792. The cubic root of 649828121 is about 866.1627456298.

The spelling of 649828121 in words is "six hundred forty-nine million, eight hundred twenty-eight thousand, one hundred twenty-one".