661405060 has 24 divisors (see below), whose sum is σ = 1470654360. Its totient is φ = 248999424.

The previous prime is 661405051. The next prime is 661405061. The reversal of 661405060 is 60504166.

661405060 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 19998784 + 641406276 = 4472^2 + 25326^2 .

It is not an unprimeable number, because it can be changed into a prime (661405061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 972315 + ... + 972994.

It is an arithmetic number, because the mean of its divisors is an integer number (61277265).

Almost surely, 2^661405060 is an apocalyptic number.

It is an amenable number.

661405060 is an abundant number, since it is smaller than the sum of its proper divisors (809249300).

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

661405060 is a wasteful number, since it uses less digits than its factorization.

661405060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945335 (or 1945333 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 661405060 is about 25717.7965619141. The cubic root of 661405060 is about 871.2761735264.

The spelling of 661405060 in words is "six hundred sixty-one million, four hundred five thousand, sixty".