649215561 has 16 divisors (see below), whose sum is σ = 871879680. Its totient is φ = 429691920.

The previous prime is 649215529. The next prime is 649215569. The reversal of 649215561 is 165512946.

649215561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 649215561 - 2⁵ = 649215529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (649215569) 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, 317380 + ... + 319418.

It is an arithmetic number, because the mean of its divisors is an integer number (54492480).

Almost surely, 2^649215561 is an apocalyptic number.

It is an amenable number.

649215561 is a deficient number, since it is larger than the sum of its proper divisors (222664119).

649215561 is a wasteful number, since it uses less digits than its factorization.

649215561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756.

The product of its digits is 64800, while the sum is 39.

The square root of 649215561 is about 25479.7088091681. The cubic root of 649215561 is about 865.8904975088.

The spelling of 649215561 in words is "six hundred forty-nine million, two hundred fifteen thousand, five hundred sixty-one".