861456853609 has 9 divisors (see below), whose sum is σ = 946901813431. Its totient is φ = 783133312720.

The previous prime is 861456853597. The next prime is 861456853661. The reversal of 861456853609 is 906358654168.

The square root of 861456853609 is 928147.

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

It can be written as a sum of positive squares in only one way, i.e., 716198301225 + 145258552384 = 846285^2 + 381128^2 .

It is not a de Polignac number, because 861456853609 - 2⁵ = 861456853577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861456853109) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10167429 + ... + 10251805.

Almost surely, 2^861456853609 is an apocalyptic number.

861456853609 is the 928147-th square number.

861456853609 is the 464074-th centered octagonal number.

It is an amenable number.

861456853609 is a deficient number, since it is larger than the sum of its proper divisors (85444959822).

861456853609 is an frugal number, since it uses more digits than its factorization.

861456853609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168776 (or 84388 counting only the distinct ones).

The product of its (nonzero) digits is 37324800, while the sum is 61.

The spelling of 861456853609 in words is "eight hundred sixty-one billion, four hundred fifty-six million, eight hundred fifty-three thousand, six hundred nine".