215809051 has 2 divisors, whose sum is σ = 215809052. Its totient is φ = 215809050.

The previous prime is 215809019. The next prime is 215809081. The reversal of 215809051 is 150908512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215809051 - 2⁵ = 215809019 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (215809081) 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, 107904525 + 107904526.

It is an arithmetic number, because the mean of its divisors is an integer number (107904526).

Almost surely, 2^215809051 is an apocalyptic number.

215809051 is a deficient number, since it is larger than the sum of its proper divisors (1).

215809051 is an equidigital number, since it uses as much as digits as its factorization.

215809051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 215809051 is about 14690.4408034613. The cubic root of 215809051 is about 599.8231432450.

The spelling of 215809051 in words is "two hundred fifteen million, eight hundred nine thousand, fifty-one".