221407493 has 2 divisors, whose sum is σ = 221407494. Its totient is φ = 221407492.

The previous prime is 221407469. The next prime is 221407531. The reversal of 221407493 is 394704122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134954689 + 86452804 = 11617^2 + 9298^2 .

It is a cyclic number.

It is not a de Polignac number, because 221407493 - 2¹⁰ = 221406469 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221400493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110703746 + 110703747.

It is an arithmetic number, because the mean of its divisors is an integer number (110703747).

Almost surely, 2^221407493 is an apocalyptic number.

It is an amenable number.

221407493 is a deficient number, since it is larger than the sum of its proper divisors (1).

221407493 is an equidigital number, since it uses as much as digits as its factorization.

221407493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 221407493 is about 14879.7679081362. The cubic root of 221407493 is about 604.9657271754.

The spelling of 221407493 in words is "two hundred twenty-one million, four hundred seven thousand, four hundred ninety-three".