221066397 has 12 divisors (see below), whose sum is σ = 326744704. Its totient is φ = 143949960.

The previous prime is 221066389. The next prime is 221066399. The reversal of 221066397 is 793660122.

221066397 is a `hidden beast` number, since 2 + 2 + 10 + 6 + 639 + 7 = 666.

It is not a de Polignac number, because 221066397 - 2³ = 221066389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221066399) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 285229 + ... + 286002.

Almost surely, 2^221066397 is an apocalyptic number.

It is an amenable number.

221066397 is a deficient number, since it is larger than the sum of its proper divisors (105678307).

221066397 is a wasteful number, since it uses less digits than its factorization.

221066397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571280 (or 571277 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 221066397 is about 14868.3017523858. The cubic root of 221066397 is about 604.6549014296.

The spelling of 221066397 in words is "two hundred twenty-one million, sixty-six thousand, three hundred ninety-seven".