1561445 has 4 divisors (see below), whose sum is σ = 1873740. Its totient is φ = 1249152.

The previous prime is 1561429. The next prime is 1561453. The reversal of 1561445 is 5441651.

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 516961 + 1044484 = 719^2 + 1022^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561445 - 2⁴ = 1561429 is a prime.

It is a super-2 number, since 2×1561445² = 4876220976050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 156140 + ... + 156149.

It is an arithmetic number, because the mean of its divisors is an integer number (468435).

2^1561445 is an apocalyptic number.

It is an amenable number.

1561445 is a deficient number, since it is larger than the sum of its proper divisors (312295).

1561445 is an equidigital number, since it uses as much as digits as its factorization.

1561445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312294.

The product of its digits is 2400, while the sum is 26.

The square root of 1561445 is about 1249.5779287423. The cubic root of 1561445 is about 116.0135982870.

The spelling of 1561445 in words is "one million, five hundred sixty-one thousand, four hundred forty-five".