1445555221 has 16 divisors (see below), whose sum is σ = 1648263168. Its totient is φ = 1254919600.

The previous prime is 1445555219. The next prime is 1445555239. The reversal of 1445555221 is 1225555441.

It is not a de Polignac number, because 1445555221 - 2¹ = 1445555219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1445555261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159276 + ... + 168106.

It is an arithmetic number, because the mean of its divisors is an integer number (103016448).

Almost surely, 2^1445555221 is an apocalyptic number.

1445555221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1445555221 is a deficient number, since it is larger than the sum of its proper divisors (202707947).

1445555221 is a wasteful number, since it uses less digits than its factorization.

1445555221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9512.

The product of its digits is 40000, while the sum is 34.

The square root of 1445555221 is about 38020.4579272791. The cubic root of 1445555221 is about 1130.6934999537.

The spelling of 1445555221 in words is "one billion, four hundred forty-five million, five hundred fifty-five thousand, two hundred twenty-one".