1661478 has 64 divisors (see below), whose sum is σ = 4354560. Its totient is φ = 410112.

The previous prime is 1661447. The next prime is 1661479. The reversal of 1661478 is 8741661.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661479) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9193 + ... + 9371.

It is an arithmetic number, because the mean of its divisors is an integer number (68040).

2^1661478 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2177280).

1661478 is an abundant number, since it is smaller than the sum of its proper divisors (2693082).

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

1661478 is a wasteful number, since it uses less digits than its factorization.

1661478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221.

The product of its digits is 8064, while the sum is 33.

The square root of 1661478 is about 1288.9833202955. The cubic root of 1661478 is about 118.4399453574.

The spelling of 1661478 in words is "one million, six hundred sixty-one thousand, four hundred seventy-eight".