650661561 has 24 divisors (see below), whose sum is σ = 1047106944. Its totient is φ = 385947360.

The previous prime is 650661533. The next prime is 650661577. The reversal of 650661561 is 165166056.

650661561 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 650661561 - 2⁶ = 650661497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (650661521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65266 + ... + 74571.

It is an arithmetic number, because the mean of its divisors is an integer number (43629456).

Almost surely, 2^650661561 is an apocalyptic number.

It is an amenable number.

650661561 is a deficient number, since it is larger than the sum of its proper divisors (396445383).

650661561 is a wasteful number, since it uses less digits than its factorization.

650661561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139901 (or 139898 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 650661561 is about 25508.0685470304. The cubic root of 650661561 is about 866.5328877500.

The spelling of 650661561 in words is "six hundred fifty million, six hundred sixty-one thousand, five hundred sixty-one".