861542245249 has 27 divisors (see below), whose sum is σ = 1013382018243. Its totient is φ = 730317103488.

The previous prime is 861542245177. The next prime is 861542245253. The reversal of 861542245249 is 942542245168.

The square root of 861542245249 is 928193.

It is a perfect power (a square), and thus also a powerful number.

861542245249 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 386865340225 + 474676905024 = 621985^2 + 688968^2 .

It is not a de Polignac number, because 861542245249 - 2⁷ = 861542245121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 861542245196 and 861542245205.

It is not an unprimeable number, because it can be changed into a prime (861542245349) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 630242364 + ... + 630243730.

Almost surely, 2^861542245249 is an apocalyptic number.

861542245249 is the 928193-rd square number.

861542245249 is the 464097-th centered octagonal number.

It is an amenable number.

861542245249 is a deficient number, since it is larger than the sum of its proper divisors (151839772994).

861542245249 is an frugal number, since it uses more digits than its factorization.

861542245249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2942 (or 1471 counting only the distinct ones).

The product of its digits is 5529600, while the sum is 52.

The spelling of 861542245249 in words is "eight hundred sixty-one billion, five hundred forty-two million, two hundred forty-five thousand, two hundred forty-nine".