221212455554 has 4 divisors (see below), whose sum is σ = 331818683334. Its totient is φ = 110606227776.

The previous prime is 221212455539. The next prime is 221212455557. The reversal of 221212455554 is 455554212122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 121851959329 + 99360496225 = 349073^2 + 315215^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221212455557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55303113887 + ... + 55303113890.

Almost surely, 2^221212455554 is an apocalyptic number.

221212455554 is a deficient number, since it is larger than the sum of its proper divisors (110606227780).

221212455554 is a wasteful number, since it uses less digits than its factorization.

221212455554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110606227779.

The product of its digits is 160000, while the sum is 38.

Adding to 221212455554 its reverse (455554212122), we get a palindrome (676766667676).

The spelling of 221212455554 in words is "two hundred twenty-one billion, two hundred twelve million, four hundred fifty-five thousand, five hundred fifty-four".