217041421 has 2 divisors, whose sum is σ = 217041422. Its totient is φ = 217041420.

The previous prime is 217041403. The next prime is 217041439. The reversal of 217041421 is 124140712.

It is a balanced prime because it is at equal distance from previous prime (217041403) and next prime (217041439).

It can be written as a sum of positive squares in only one way, i.e., 212838921 + 4202500 = 14589^2 + 2050^2 .

It is a cyclic number.

It is not a de Polignac number, because 217041421 - 2¹⁷ = 216910349 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 217041392 and 217041401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217041491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108520710 + 108520711.

It is an arithmetic number, because the mean of its divisors is an integer number (108520711).

Almost surely, 2^217041421 is an apocalyptic number.

It is an amenable number.

217041421 is a deficient number, since it is larger than the sum of its proper divisors (1).

217041421 is an equidigital number, since it uses as much as digits as its factorization.

217041421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 217041421 is about 14732.3257159214. The cubic root of 217041421 is about 600.9627331191.

The spelling of 217041421 in words is "two hundred seventeen million, forty-one thousand, four hundred twenty-one".