215778047 has 2 divisors, whose sum is σ = 215778048. Its totient is φ = 215778046.

The previous prime is 215778029. The next prime is 215778049. The reversal of 215778047 is 740877512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215778047 - 2⁸ = 215777791 is a prime.

Together with 215778049, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 215777995 and 215778013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215778049) 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 as a sum of consecutive naturals, namely, 107889023 + 107889024.

It is an arithmetic number, because the mean of its divisors is an integer number (107889024).

Almost surely, 2^215778047 is an apocalyptic number.

215778047 is a deficient number, since it is larger than the sum of its proper divisors (1).

215778047 is an equidigital number, since it uses as much as digits as its factorization.

215778047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 109760, while the sum is 41.

The square root of 215778047 is about 14689.3855215254. The cubic root of 215778047 is about 599.7944175308.

The spelling of 215778047 in words is "two hundred fifteen million, seven hundred seventy-eight thousand, forty-seven".