650661021 has 24 divisors (see below), whose sum is σ = 988808184. Its totient is φ = 411747840.

The previous prime is 650660999. The next prime is 650661029. The reversal of 650661021 is 120166056.

It is a happy number.

650661021 is a `hidden beast` number, since 650 + 6 + 6 + 1 + 0 + 2 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 134235396 + 516425625 = 11586^2 + 22725^2 .

It is not a de Polignac number, because 650661021 - 2¹⁷ = 650529949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (650661029) 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, 10176 + ... + 37481.

It is an arithmetic number, because the mean of its divisors is an integer number (41200341).

Almost surely, 2^650661021 is an apocalyptic number.

It is an amenable number.

650661021 is a deficient number, since it is larger than the sum of its proper divisors (338147163).

650661021 is a wasteful number, since it uses less digits than its factorization.

650661021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47741 (or 47738 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 650661021 is about 25508.0579621421. The cubic root of 650661021 is about 866.5326480310.

The spelling of 650661021 in words is "six hundred fifty million, six hundred sixty-one thousand, twenty-one".