221394555 has 48 divisors (see below), whose sum is σ = 417924000. Its totient is φ = 107993088.

The previous prime is 221394541. The next prime is 221394557. The reversal of 221394555 is 555493122.

It is a happy number.

221394555 is a `hidden beast` number, since 2 + 2 + 13 + 94 + 555 = 666.

It is not a de Polignac number, because 221394555 - 2⁷ = 221394427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221394557) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20331 + ... + 29259.

It is an arithmetic number, because the mean of its divisors is an integer number (8706750).

Almost surely, 2^221394555 is an apocalyptic number.

221394555 is a deficient number, since it is larger than the sum of its proper divisors (196529445).

221394555 is a wasteful number, since it uses less digits than its factorization.

221394555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8988 (or 8985 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 221394555 is about 14879.3331503801. Note that the first 3 decimals coincide. The cubic root of 221394555 is about 604.9539431733.

The spelling of 221394555 in words is "two hundred twenty-one million, three hundred ninety-four thousand, five hundred fifty-five".