215622779891 has 2 divisors, whose sum is σ = 215622779892. Its totient is φ = 215622779890.

The previous prime is 215622779873. The next prime is 215622779923. The reversal of 215622779891 is 198977226512.

215622779891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215622779891 - 2²⁶ = 215555671027 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 215622779891.

It is not a weakly prime, because it can be changed into another prime (215622779851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107811389945 + 107811389946.

It is an arithmetic number, because the mean of its divisors is an integer number (107811389946).

Almost surely, 2^215622779891 is an apocalyptic number.

215622779891 is a deficient number, since it is larger than the sum of its proper divisors (1).

215622779891 is an equidigital number, since it uses as much as digits as its factorization.

215622779891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7620480, while the sum is 59.

The spelling of 215622779891 in words is "two hundred fifteen billion, six hundred twenty-two million, seven hundred seventy-nine thousand, eight hundred ninety-one".