2251330221 has 16 divisors (see below), whose sum is σ = 3503591424. Its totient is φ = 1259102064.

The previous prime is 2251330219. The next prime is 2251330223. The reversal of 2251330221 is 1220331522.

It is an interprime number because it is at equal distance from previous prime (2251330219) and next prime (2251330223).

It is not a de Polignac number, because 2251330221 - 2¹ = 2251330219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2251330223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1139505 + ... + 1141478.

It is an arithmetic number, because the mean of its divisors is an integer number (218974464).

Almost surely, 2^2251330221 is an apocalyptic number.

2251330221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2251330221 is a deficient number, since it is larger than the sum of its proper divisors (1252261203).

2251330221 is a wasteful number, since it uses less digits than its factorization.

2251330221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2281040.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 2251330221 is about 47448.1845911938. The cubic root of 2251330221 is about 1310.6288806930.

Adding to 2251330221 its reverse (1220331522), we get a palindrome (3471661743).

The spelling of 2251330221 in words is "two billion, two hundred fifty-one million, three hundred thirty thousand, two hundred twenty-one".