1661430 has 16 divisors (see below), whose sum is σ = 3987504. Its totient is φ = 443040.

The previous prime is 1661353. The next prime is 1661431. The reversal of 1661430 is 341661.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1661397 and 1661406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27661 + ... + 27720.

It is an arithmetic number, because the mean of its divisors is an integer number (249219).

2^1661430 is an apocalyptic number.

1661430 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661430 is an abundant number, since it is smaller than the sum of its proper divisors (2326074).

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

1661430 is a wasteful number, since it uses less digits than its factorization.

1661430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55391.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 1661430 is about 1288.9647008355. The cubic root of 1661430 is about 118.4388047721.

It can be divided in two parts, 166 and 1430, that added together give a triangular number (1596 = T₅₆).

The spelling of 1661430 in words is "one million, six hundred sixty-one thousand, four hundred thirty".