2878162561 has 4 divisors (see below), whose sum is σ = 2878944772. Its totient is φ = 2877380352.

The previous prime is 2878162513. The next prime is 2878162589. The reversal of 2878162561 is 1652618782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1652618782 = 2 ⋅826309391.

It can be written as a sum of positive squares in 2 ways, for example, as 1456872561 + 1421290000 = 38169^2 + 37700^2 .

It is a cyclic number.

It is not a de Polignac number, because 2878162561 - 2¹⁹ = 2877638273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2878162061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385560 + ... + 392953.

It is an arithmetic number, because the mean of its divisors is an integer number (719736193).

Almost surely, 2^2878162561 is an apocalyptic number.

It is an amenable number.

2878162561 is a deficient number, since it is larger than the sum of its proper divisors (782211).

2878162561 is an equidigital number, since it uses as much as digits as its factorization.

2878162561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782210.

The product of its digits is 322560, while the sum is 46.

The square root of 2878162561 is about 53648.5094014736. The cubic root of 2878162561 is about 1422.4546845336.

The spelling of 2878162561 in words is "two billion, eight hundred seventy-eight million, one hundred sixty-two thousand, five hundred sixty-one".