1561050665 has 8 divisors (see below), whose sum is σ = 1896973440. Its totient is φ = 1233032112.

The previous prime is 1561050649. The next prime is 1561050671. The reversal of 1561050665 is 5660501651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1561050665 - 2⁴ = 1561050649 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1975619 + ... + 1976408.

It is an arithmetic number, because the mean of its divisors is an integer number (237121680).

Almost surely, 2^1561050665 is an apocalyptic number.

It is an amenable number.

1561050665 is a deficient number, since it is larger than the sum of its proper divisors (335922775).

1561050665 is an equidigital number, since it uses as much as digits as its factorization.

1561050665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3952111.

The product of its (nonzero) digits is 27000, while the sum is 35.

The square root of 1561050665 is about 39510.1337001028. The cubic root of 1561050665 is about 1160.0383124980.

The spelling of 1561050665 in words is "one billion, five hundred sixty-one million, fifty thousand, six hundred sixty-five".