861620459 has 10 divisors (see below), whose sum is σ = 1005166860. Its totient is φ = 738529764.

The previous prime is 861620447. The next prime is 861620509. The reversal of 861620459 is 954026168.

It is a happy number.

It is not a de Polignac number, because 861620459 - 2⁸ = 861620203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861620159) by changing a digit.

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 9 ways as a sum of consecutive naturals, for example, 177029 + ... + 181830.

It is an arithmetic number, because the mean of its divisors is an integer number (100516686).

Almost surely, 2^861620459 is an apocalyptic number.

861620459 is a deficient number, since it is larger than the sum of its proper divisors (143546401).

861620459 is an frugal number, since it uses more digits than its factorization.

861620459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358887 (or 358866 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 861620459 is about 29353.3721912832. The cubic root of 861620459 is about 951.5654555155.

The spelling of 861620459 in words is "eight hundred sixty-one million, six hundred twenty thousand, four hundred fifty-nine".