211551097 has 2 divisors, whose sum is σ = 211551098. Its totient is φ = 211551096.

The previous prime is 211551071. The next prime is 211551101. The reversal of 211551097 is 790155112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111070521 + 100480576 = 10539^2 + 10024^2 .

It is a cyclic number.

It is not a de Polignac number, because 211551097 - 2²³ = 203162489 is a prime.

It is equal to p_11682517 and since 211551097 and 11682517 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (211551797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105775548 + 105775549.

It is an arithmetic number, because the mean of its divisors is an integer number (105775549).

Almost surely, 2^211551097 is an apocalyptic number.

It is an amenable number.

211551097 is a deficient number, since it is larger than the sum of its proper divisors (1).

211551097 is an equidigital number, since it uses as much as digits as its factorization.

211551097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3150, while the sum is 31.

The square root of 211551097 is about 14544.7962172043. The cubic root of 211551097 is about 595.8520354354.

The spelling of 211551097 in words is "two hundred eleven million, five hundred fifty-one thousand, ninety-seven".