1561287 has 48 divisors (see below), whose sum is σ = 2808960. Its totient is φ = 762048.

The previous prime is 1561279. The next prime is 1561303. The reversal of 1561287 is 7821651.

It is not a de Polignac number, because 1561287 - 2³ = 1561279 is a prime.

1561287 is a modest number, since divided by 1287 gives 156 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561247) 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 47 ways as a sum of consecutive naturals, for example, 36288 + ... + 36330.

It is an arithmetic number, because the mean of its divisors is an integer number (58520).

2^1561287 is an apocalyptic number.

1561287 is a deficient number, since it is larger than the sum of its proper divisors (1247673).

1561287 is a wasteful number, since it uses less digits than its factorization.

1561287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92 (or 85 counting only the distinct ones).

The product of its digits is 3360, while the sum is 30.

The square root of 1561287 is about 1249.5147057958. The cubic root of 1561287 is about 116.0096850812.

The spelling of 1561287 in words is "one million, five hundred sixty-one thousand, two hundred eighty-seven".