1915516561 has 8 divisors (see below), whose sum is σ = 2189633600. Its totient is φ = 1641517488.

The previous prime is 1915516549. The next prime is 1915516591. The reversal of 1915516561 is 1656155191.

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 1915516561 - 2¹⁷ = 1915385489 is a prime.

It is a super-3 number, since 3×1915516561³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1915516541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8590 + ... + 62488.

It is an arithmetic number, because the mean of its divisors is an integer number (273704200).

Almost surely, 2^1915516561 is an apocalyptic number.

It is an amenable number.

1915516561 is a deficient number, since it is larger than the sum of its proper divisors (274117039).

1915516561 is an equidigital number, since it uses as much as digits as its factorization.

1915516561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58983.

The product of its digits is 40500, while the sum is 40.

The square root of 1915516561 is about 43766.6146851684. The cubic root of 1915516561 is about 1241.9248117499.

The spelling of 1915516561 in words is "one billion, nine hundred fifteen million, five hundred sixteen thousand, five hundred sixty-one".