2561835815 has 64 divisors (see below), whose sum is σ = 4041474048. Its totient is φ = 1512259200.

The previous prime is 2561835803. The next prime is 2561835907. The reversal of 2561835815 is 5185381652.

It is not a de Polignac number, because 2561835815 - 2⁸ = 2561835559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 558662 + ... + 563228.

It is an arithmetic number, because the mean of its divisors is an integer number (63148032).

Almost surely, 2^2561835815 is an apocalyptic number.

2561835815 is a deficient number, since it is larger than the sum of its proper divisors (1479638233).

2561835815 is a wasteful number, since it uses less digits than its factorization.

2561835815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4668.

The product of its digits is 288000, while the sum is 44.

The square root of 2561835815 is about 50614.5810513137. The cubic root of 2561835815 is about 1368.3076791541.

The spelling of 2561835815 in words is "two billion, five hundred sixty-one million, eight hundred thirty-five thousand, eight hundred fifteen".