661478 has 16 divisors (see below), whose sum is σ = 1050624. Its totient is φ = 311880.

The previous prime is 661477. The next prime is 661481. The reversal of 661478 is 874166.

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 661478.

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

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2801 + ... + 3027.

It is an arithmetic number, because the mean of its divisors is an integer number (65664).

2⁶⁶¹⁴⁷⁸ is an apocalyptic number.

661478 is a deficient number, since it is larger than the sum of its proper divisors (389146).

661478 is a wasteful number, since it uses less digits than its factorization.

661478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307.

The product of its digits is 8064, while the sum is 32.

The square root of 661478 is about 813.3129778874. The cubic root of 661478 is about 87.1308200571.

The spelling of 661478 in words is "six hundred sixty-one thousand, four hundred seventy-eight".