861312772 has 12 divisors (see below), whose sum is σ = 1507607500. Its totient is φ = 430567776.

The previous prime is 861312757. The next prime is 861312779. The reversal of 861312772 is 277213168.

It can be written as a sum of positive squares in 2 ways, for example, as 654643396 + 206669376 = 25586^2 + 14376^2 .

It is not an unprimeable number, because it can be changed into a prime (861312779) 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, 2854 + ... + 41602.

Almost surely, 2^861312772 is an apocalyptic number.

It is an amenable number.

861312772 is a deficient number, since it is larger than the sum of its proper divisors (646294728).

861312772 is a wasteful number, since it uses less digits than its factorization.

861312772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44310 (or 44308 counting only the distinct ones).

The product of its digits is 28224, while the sum is 37.

The square root of 861312772 is about 29348.1306389351. The cubic root of 861312772 is about 951.4521731627.

The spelling of 861312772 in words is "eight hundred sixty-one million, three hundred twelve thousand, seven hundred seventy-two".