661363530 has 64 divisors (see below), whose sum is σ = 1635033600. Its totient is φ = 171085824.

The previous prime is 661363523. The next prime is 661363561. The reversal of 661363530 is 35363166.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 661363491 and 661363500.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 497727 + ... + 499053.

It is an arithmetic number, because the mean of its divisors is an integer number (25547400).

Almost surely, 2^661363530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661363530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (817516800).

661363530 is an abundant number, since it is smaller than the sum of its proper divisors (973670070).

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

661363530 is a wasteful number, since it uses less digits than its factorization.

661363530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823.

The product of its (nonzero) digits is 29160, while the sum is 33.

The square root of 661363530 is about 25716.9891317005. The cubic root of 661363530 is about 871.2579371691.

The spelling of 661363530 in words is "six hundred sixty-one million, three hundred sixty-three thousand, five hundred thirty".