1961609 has 4 divisors (see below), whose sum is σ = 2112516. Its totient is φ = 1810704.

The previous prime is 1961593. The next prime is 1961623. The reversal of 1961609 is 9061691.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 198025 + 1763584 = 445^2 + 1328^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961609 - 2⁴ = 1961593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1961669) 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 3 ways as a sum of consecutive naturals, for example, 75434 + ... + 75459.

It is an arithmetic number, because the mean of its divisors is an integer number (528129).

2^1961609 is an apocalyptic number.

It is an amenable number.

1961609 is a deficient number, since it is larger than the sum of its proper divisors (150907).

1961609 is a wasteful number, since it uses less digits than its factorization.

1961609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150906.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 1961609 is about 1400.5745249718. The cubic root of 1961609 is about 125.1807305658.

The spelling of 1961609 in words is "one million, nine hundred sixty-one thousand, six hundred nine".