2155221445 has 8 divisors (see below), whose sum is σ = 2785209336. Its totient is φ = 1591548096.

The previous prime is 2155221421. The next prime is 2155221451. The reversal of 2155221445 is 5441225512.

It can be written as a sum of positive squares in 4 ways, for example, as 18378369 + 2136843076 = 4287^2 + 46226^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2155221445 - 2¹¹ = 2155219397 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16578562 + ... + 16578691.

It is an arithmetic number, because the mean of its divisors is an integer number (348151167).

Almost surely, 2^2155221445 is an apocalyptic number.

It is an amenable number.

2155221445 is a deficient number, since it is larger than the sum of its proper divisors (629987891).

2155221445 is a wasteful number, since it uses less digits than its factorization.

2155221445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33157271.

The product of its digits is 16000, while the sum is 31.

The square root of 2155221445 is about 46424.3626235191. The cubic root of 2155221445 is about 1291.7068616189.

Adding to 2155221445 its reverse (5441225512), we get a palindrome (7596446957).

The spelling of 2155221445 in words is "two billion, one hundred fifty-five million, two hundred twenty-one thousand, four hundred forty-five".