661560340 has 24 divisors (see below), whose sum is σ = 1587745152. Its totient is φ = 226820640.

The previous prime is 661560331. The next prime is 661560343. The reversal of 661560340 is 43065166.

661560340 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661560343) 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, 2362576 + ... + 2362855.

It is an arithmetic number, because the mean of its divisors is an integer number (66156048).

Almost surely, 2^661560340 is an apocalyptic number.

It is an amenable number.

661560340 is an abundant number, since it is smaller than the sum of its proper divisors (926184812).

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

661560340 is a wasteful number, since it uses less digits than its factorization.

661560340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4725447 (or 4725445 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 661560340 is about 25720.8153058957. The cubic root of 661560340 is about 871.3443522095.

It can be divided in two parts, 661 and 560340, that added together give a square (561001 = 749²).

The spelling of 661560340 in words is "six hundred sixty-one million, five hundred sixty thousand, three hundred forty".