861278250722 has 18 divisors (see below), whose sum is σ = 1304316883233. Its totient is φ = 426544900152.

The previous prime is 861278250713. The next prime is 861278250751. The reversal of 861278250722 is 227052872168.

It can be written as a sum of positive squares in 2 ways, for example, as 581541982921 + 279736267801 = 762589^2 + 528901^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=656231.

It is a Duffinian 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 8 ways as a sum of consecutive naturals, for example, 140430368 + ... + 140436500.

Almost surely, 2^861278250722 is an apocalyptic number.

861278250722 is a deficient number, since it is larger than the sum of its proper divisors (443038632511).

861278250722 is an frugal number, since it uses more digits than its factorization.

861278250722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12482 (or 6242 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 50.

Multiplying 861278250722 by its sum of digits (50), we get a square (43063912536100 = 6562310²).

The spelling of 861278250722 in words is "eight hundred sixty-one billion, two hundred seventy-eight million, two hundred fifty thousand, seven hundred twenty-two".