1661525 has 12 divisors (see below), whose sum is σ = 2111844. Its totient is φ = 1296000.

The previous prime is 1661519. The next prime is 1661549. The reversal of 1661525 is 5251661.

It can be written as a sum of positive squares in 6 ways, for example, as 128881 + 1532644 = 359^2 + 1238^2 .

It is not a de Polignac number, because 1661525 - 2¹² = 1657429 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1661494 and 1661503.

It is a congruent 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 11 ways as a sum of consecutive naturals, for example, 215 + ... + 1835.

It is an arithmetic number, because the mean of its divisors is an integer number (175987).

2^1661525 is an apocalyptic number.

It is an amenable number.

1661525 is a deficient number, since it is larger than the sum of its proper divisors (450319).

1661525 is a wasteful number, since it uses less digits than its factorization.

1661525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672 (or 1667 counting only the distinct ones).

The product of its digits is 1800, while the sum is 26.

The square root of 1661525 is about 1289.0015515894. The cubic root of 1661525 is about 118.4410621592.

The spelling of 1661525 in words is "one million, six hundred sixty-one thousand, five hundred twenty-five".