661480 has 32 divisors (see below), whose sum is σ = 1555200. Its totient is φ = 252736.

The previous prime is 661477. The next prime is 661481. The reversal of 661480 is 84166.

661480 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (661481) 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, 561 + ... + 1279.

It is an arithmetic number, because the mean of its divisors is an integer number (48600).

2⁶⁶¹⁴⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (777600).

661480 is an abundant number, since it is smaller than the sum of its proper divisors (893720).

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

661480 is a wasteful number, since it uses less digits than its factorization.

661480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 661480 is about 813.3142074254. The cubic root of 661480 is about 87.1309078713.

The spelling of 661480 in words is "six hundred sixty-one thousand, four hundred eighty".