561665020 has 48 divisors (see below), whose sum is σ = 1368138240. Its totient is φ = 189693504.

The previous prime is 561664969. The next prime is 561665033. The reversal of 561665020 is 20566165.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 20560 + ... + 39319.

It is an arithmetic number, because the mean of its divisors is an integer number (28502880).

Almost surely, 2^561665020 is an apocalyptic number.

It is an amenable number.

561665020 is an abundant number, since it is smaller than the sum of its proper divisors (806473220).

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

561665020 is a wasteful number, since it uses less digits than its factorization.

561665020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59962 (or 59960 counting only the distinct ones).

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

The square root of 561665020 is about 23699.4729899211. The cubic root of 561665020 is about 825.0731591076.

The spelling of 561665020 in words is "five hundred sixty-one million, six hundred sixty-five thousand, twenty".