215450551 has 2 divisors, whose sum is σ = 215450552. Its totient is φ = 215450550.

The previous prime is 215450549. The next prime is 215450561. The reversal of 215450551 is 155054512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215450551 - 2¹ = 215450549 is a prime.

Together with 215450549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215450561) 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, 107725275 + 107725276.

It is an arithmetic number, because the mean of its divisors is an integer number (107725276).

Almost surely, 2^215450551 is an apocalyptic number.

215450551 is a deficient number, since it is larger than the sum of its proper divisors (1).

215450551 is an equidigital number, since it uses as much as digits as its factorization.

215450551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5000, while the sum is 28.

The square root of 215450551 is about 14678.2339196512. The cubic root of 215450551 is about 599.4908189392.

The spelling of 215450551 in words is "two hundred fifteen million, four hundred fifty thousand, five hundred fifty-one".