213305551 has 2 divisors, whose sum is σ = 213305552. Its totient is φ = 213305550.

The previous prime is 213305537. The next prime is 213305557. The reversal of 213305551 is 155503312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 213305551 - 2²¹ = 211208399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213305557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106652775 + 106652776.

It is an arithmetic number, because the mean of its divisors is an integer number (106652776).

Almost surely, 2^213305551 is an apocalyptic number.

213305551 is a deficient number, since it is larger than the sum of its proper divisors (1).

213305551 is an equidigital number, since it uses as much as digits as its factorization.

213305551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 25.

The square root of 213305551 is about 14604.9837726716. The cubic root of 213305551 is about 597.4946934398.

Adding to 213305551 its reverse (155503312), we get a palindrome (368808863).

The spelling of 213305551 in words is "two hundred thirteen million, three hundred five thousand, five hundred fifty-one".