661106580 has 48 divisors (see below), whose sum is σ = 1855586880. Its totient is φ = 175867648.

The previous prime is 661106569. The next prime is 661106599. The reversal of 661106580 is 85601166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11992 + ... + 38288.

It is an arithmetic number, because the mean of its divisors is an integer number (38658060).

Almost surely, 2^661106580 is an apocalyptic number.

661106580 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

661106580 is an abundant number, since it is smaller than the sum of its proper divisors (1194480300).

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

661106580 is a wasteful number, since it uses less digits than its factorization.

661106580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26728 (or 26726 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 661106580 is about 25711.9929215921. The cubic root of 661106580 is about 871.1450901416.

The spelling of 661106580 in words is "six hundred sixty-one million, one hundred six thousand, five hundred eighty".