221501404 has 12 divisors (see below), whose sum is σ = 387755424. Its totient is φ = 110714144.

The previous prime is 221501387. The next prime is 221501429. The reversal of 221501404 is 404105122.

221501404 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8109 + ... + 22555.

It is an arithmetic number, because the mean of its divisors is an integer number (32312952).

Almost surely, 2^221501404 is an apocalyptic number.

It is an amenable number.

221501404 is a deficient number, since it is larger than the sum of its proper divisors (166254020).

221501404 is a wasteful number, since it uses less digits than its factorization.

221501404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18284 (or 18282 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 221501404 is about 14882.9232343649. The cubic root of 221501404 is about 605.0512480778.

Adding to 221501404 its reverse (404105122), we get a palindrome (625606526).

The spelling of 221501404 in words is "two hundred twenty-one million, five hundred one thousand, four hundred four".