661520650 has 48 divisors (see below), whose sum is σ = 1440532800. Its totient is φ = 221270400.

The previous prime is 661520647. The next prime is 661520689. The reversal of 661520650 is 56025166.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8700 + ... + 37399.

It is an arithmetic number, because the mean of its divisors is an integer number (30011100).

Almost surely, 2^661520650 is an apocalyptic number.

661520650 is an abundant number, since it is smaller than the sum of its proper divisors (779012150).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661520650 is a wasteful number, since it uses less digits than its factorization.

661520650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46159 (or 46154 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 661520650 is about 25720.0437402427. The cubic root of 661520650 is about 871.3269265634.

The spelling of 661520650 in words is "six hundred sixty-one million, five hundred twenty thousand, six hundred fifty".