221540478 has 8 divisors (see below), whose sum is σ = 443080968. Its totient is φ = 73846824.

The previous prime is 221540443. The next prime is 221540479. The reversal of 221540478 is 874045122.

It is a sphenic number, since it is the product of 3 distinct primes.

221540478 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221540479) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18461701 + ... + 18461712.

It is an arithmetic number, because the mean of its divisors is an integer number (55385121).

Almost surely, 2^221540478 is an apocalyptic number.

221540478 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221540478 is a wasteful number, since it uses less digits than its factorization.

221540478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36923418.

The product of its (nonzero) digits is 17920, while the sum is 33.

The square root of 221540478 is about 14884.2358890203. The cubic root of 221540478 is about 605.0868240486.

The spelling of 221540478 in words is "two hundred twenty-one million, five hundred forty thousand, four hundred seventy-eight".