215995789 has 2 divisors, whose sum is σ = 215995790. Its totient is φ = 215995788.

The previous prime is 215995753. The next prime is 215995823. The reversal of 215995789 is 987599512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122544900 + 93450889 = 11070^2 + 9667^2 .

It is a cyclic number.

It is not a de Polignac number, because 215995789 - 2¹⁵ = 215963021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215995189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107997894 + 107997895.

It is an arithmetic number, because the mean of its divisors is an integer number (107997895).

Almost surely, 2^215995789 is an apocalyptic number.

It is an amenable number.

215995789 is a deficient number, since it is larger than the sum of its proper divisors (1).

215995789 is an equidigital number, since it uses as much as digits as its factorization.

215995789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2041200, while the sum is 55.

The square root of 215995789 is about 14696.7951948716. The cubic root of 215995789 is about 599.9961009006.

It can be divided in two parts, 215 and 995789, that added together give a square (996004 = 998²).

The spelling of 215995789 in words is "two hundred fifteen million, nine hundred ninety-five thousand, seven hundred eighty-nine".