221543479 has 2 divisors, whose sum is σ = 221543480. Its totient is φ = 221543478.

The previous prime is 221543471. The next prime is 221543489. The reversal of 221543479 is 974345122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221543479 - 2³ = 221543471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221543471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110771739 + 110771740.

It is an arithmetic number, because the mean of its divisors is an integer number (110771740).

Almost surely, 2^221543479 is an apocalyptic number.

221543479 is a deficient number, since it is larger than the sum of its proper divisors (1).

221543479 is an equidigital number, since it uses as much as digits as its factorization.

221543479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 37.

The square root of 221543479 is about 14884.3367000347. The cubic root of 221543479 is about 605.0895562165.

The spelling of 221543479 in words is "two hundred twenty-one million, five hundred forty-three thousand, four hundred seventy-nine".