2781531816 has 64 divisors (see below), whose sum is σ = 8116346880. Its totient is φ = 777812160.

The previous prime is 2781531757. The next prime is 2781531827. The reversal of 2781531816 is 6181351872.

2781531816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168240 + ... + 184031.

It is an arithmetic number, because the mean of its divisors is an integer number (126817920).

Almost surely, 2^2781531816 is an apocalyptic number.

It is an amenable number.

2781531816 is an abundant number, since it is smaller than the sum of its proper divisors (5334815064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2781531816 is a wasteful number, since it uses less digits than its factorization.

2781531816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352334 (or 352330 counting only the distinct ones).

The product of its digits is 80640, while the sum is 42.

The square root of 2781531816 is about 52740.2295785674. The cubic root of 2781531816 is about 1406.3540794710.

The spelling of 2781531816 in words is "two billion, seven hundred eighty-one million, five hundred thirty-one thousand, eight hundred sixteen".