1561042065 has 16 divisors (see below), whose sum is σ = 2724728256. Its totient is φ = 756868800.

The previous prime is 1561042013. The next prime is 1561042081. The reversal of 1561042065 is 5602401651.

It is not a de Polignac number, because 1561042065 - 2⁹ = 1561041553 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4730266 + ... + 4730595.

It is an arithmetic number, because the mean of its divisors is an integer number (170295516).

Almost surely, 2^1561042065 is an apocalyptic number.

1561042065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561042065 is a deficient number, since it is larger than the sum of its proper divisors (1163686191).

1561042065 is a wasteful number, since it uses less digits than its factorization.

1561042065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9460880.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 1561042065 is about 39510.0248671144. The cubic root of 1561042065 is about 1160.0361822345.

It can be divided in two parts, 15610 and 42065, that added together give a palindrome (57675).

The spelling of 1561042065 in words is "one billion, five hundred sixty-one million, forty-two thousand, sixty-five".