1878273561 has 4 divisors (see below), whose sum is σ = 2504364752. Its totient is φ = 1252182372.

The previous prime is 1878273517. The next prime is 1878273569. The reversal of 1878273561 is 1653728781.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1878273561 - 2¹¹ = 1878271513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1878273561.

It is not an unprimeable number, because it can be changed into a prime (1878273569) 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, 313045591 + ... + 313045596.

It is an arithmetic number, because the mean of its divisors is an integer number (626091188).

Almost surely, 2^1878273561 is an apocalyptic number.

It is an amenable number.

1878273561 is a deficient number, since it is larger than the sum of its proper divisors (626091191).

1878273561 is an equidigital number, since it uses as much as digits as its factorization.

1878273561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626091190.

The product of its digits is 564480, while the sum is 48.

The square root of 1878273561 is about 43339.0535314282. The cubic root of 1878273561 is about 1233.8232462167.

The spelling of 1878273561 in words is "one billion, eight hundred seventy-eight million, two hundred seventy-three thousand, five hundred sixty-one".