2561894615 has 16 divisors (see below), whose sum is σ = 3608415552. Its totient is φ = 1709247744.

The previous prime is 2561894581. The next prime is 2561894623. The reversal of 2561894615 is 5164981652.

It is a cyclic number.

It is not a de Polignac number, because 2561894615 - 2²² = 2557700311 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2561894615.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 987854 + ... + 990443.

It is an arithmetic number, because the mean of its divisors is an integer number (225525972).

Almost surely, 2^2561894615 is an apocalyptic number.

2561894615 is a deficient number, since it is larger than the sum of its proper divisors (1046520937).

2561894615 is a wasteful number, since it uses less digits than its factorization.

2561894615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978346.

The product of its digits is 518400, while the sum is 47.

The square root of 2561894615 is about 50615.1619082662. The cubic root of 2561894615 is about 1368.3181476725.

The spelling of 2561894615 in words is "two billion, five hundred sixty-one million, eight hundred ninety-four thousand, six hundred fifteen".