661470 has 32 divisors (see below), whose sum is σ = 1682208. Its totient is φ = 165888.

The previous prime is 661459. The next prime is 661477. The reversal of 661470 is 74166.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 661470.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 661470.

It is not an unprimeable number, because it can be changed into a prime (661477) by changing a digit.

661470 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139 + ... + 1158.

It is an arithmetic number, because the mean of its divisors is an integer number (52569).

2⁶⁶¹⁴⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661470, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841104).

661470 is an abundant number, since it is smaller than the sum of its proper divisors (1020738).

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

661470 is a wasteful number, since it uses less digits than its factorization.

661470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 661470 is about 813.3080597166. The cubic root of 661470 is about 87.1304687986.

It can be divided in two parts, 66 and 1470, that multiplied together give a triangular number (97020 = T₄₄₀).

The spelling of 661470 in words is "six hundred sixty-one thousand, four hundred seventy".