861246409 has 3 divisors (see below), whose sum is σ = 861275757. Its totient is φ = 861217062.

The previous prime is 861246403. The next prime is 861246473. The reversal of 861246409 is 904642168.

The square root of 861246409 is 29347.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 861246409 - 2¹⁵ = 861213641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861246403) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 14674 + ... + 44020.

It is an arithmetic number, because the mean of its divisors is an integer number (287091919).

Almost surely, 2^861246409 is an apocalyptic number.

861246409 is the 29347-th square number.

861246409 is the 14674-th centered octagonal number.

It is an amenable number.

861246409 is a deficient number, since it is larger than the sum of its proper divisors (29348).

861246409 is an frugal number, since it uses more digits than its factorization.

861246409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58694 (or 29347 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The cubic root of 861246409 is about 951.4277364949.

Multiplying 861246409 by its product of nonzero digits (82944), we get a square (71435222148096 = 8451936²).

The spelling of 861246409 in words is "eight hundred sixty-one million, two hundred forty-six thousand, four hundred nine".