861615493 has 2 divisors, whose sum is σ = 861615494. Its totient is φ = 861615492.

The previous prime is 861615473. The next prime is 861615563. The reversal of 861615493 is 394516168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 860072929 + 1542564 = 29327^2 + 1242^2 .

It is a cyclic number.

It is not a de Polignac number, because 861615493 - 2⁹ = 861614981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861615413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430807746 + 430807747.

It is an arithmetic number, because the mean of its divisors is an integer number (430807747).

Almost surely, 2^861615493 is an apocalyptic number.

It is an amenable number.

861615493 is a deficient number, since it is larger than the sum of its proper divisors (1).

861615493 is an equidigital number, since it uses as much as digits as its factorization.

861615493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 43.

The square root of 861615493 is about 29353.2876012211. The cubic root of 861615493 is about 951.5636273776.

The spelling of 861615493 in words is "eight hundred sixty-one million, six hundred fifteen thousand, four hundred ninety-three".