221540479 has 2 divisors, whose sum is σ = 221540480. Its totient is φ = 221540478.

The previous prime is 221540443. The next prime is 221540533. The reversal of 221540479 is 974045122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221540479 - 2¹⁵ = 221507711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221543479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110770239 + 110770240.

It is an arithmetic number, because the mean of its divisors is an integer number (110770240).

Almost surely, 2^221540479 is an apocalyptic number.

221540479 is a deficient number, since it is larger than the sum of its proper divisors (1).

221540479 is an equidigital number, since it uses as much as digits as its factorization.

221540479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 221540479 is about 14884.2359226129. The cubic root of 221540479 is about 605.0868249590.

The spelling of 221540479 in words is "two hundred twenty-one million, five hundred forty thousand, four hundred seventy-nine".