221378641 has 8 divisors (see below), whose sum is σ = 255710304. Its totient is φ = 189414720.

The previous prime is 221378629. The next prime is 221378669. The reversal of 221378641 is 146873122.

221378641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 221378641 - 2⁵ = 221378609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221378597 and 221378606.

It is not an unprimeable number, because it can be changed into a prime (221378681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 591735 + ... + 592108.

It is an arithmetic number, because the mean of its divisors is an integer number (31963788).

Almost surely, 2^221378641 is an apocalyptic number.

It is an amenable number.

221378641 is a deficient number, since it is larger than the sum of its proper divisors (34331663).

221378641 is a wasteful number, since it uses less digits than its factorization.

221378641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1183871.

The product of its digits is 16128, while the sum is 34.

The square root of 221378641 is about 14878.7983721805. The cubic root of 221378641 is about 604.9394479844.

The spelling of 221378641 in words is "two hundred twenty-one million, three hundred seventy-eight thousand, six hundred forty-one".