1661530 has 16 divisors (see below), whose sum is σ = 3221064. Its totient is φ = 613440.

The previous prime is 1661519. The next prime is 1661549. The reversal of 1661530 is 351661.

It can be written as a sum of positive squares in 4 ways, for example, as 1229881 + 431649 = 1109^2 + 657^2 .

It is an Ulam number.

It is an unprimeable number.

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, 6261 + ... + 6520.

2^1661530 is an apocalyptic number.

1661530 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661530 is a deficient number, since it is larger than the sum of its proper divisors (1559534).

1661530 is a wasteful number, since it uses less digits than its factorization.

1661530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12801.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 1661530 is about 1289.0034910736. The cubic root of 1661530 is about 118.4411809667.

The spelling of 1661530 in words is "one million, six hundred sixty-one thousand, five hundred thirty".