2154244221 has 8 divisors (see below), whose sum is σ = 3191472960. Its totient is φ = 1436162796.

The previous prime is 2154244217. The next prime is 2154244223. The reversal of 2154244221 is 1224424512.

It is a happy number.

2154244221 is a `hidden beast` number, since 2 + 15 + 424 + 4 + 221 = 666.

It is not a de Polignac number, because 2154244221 - 2² = 2154244217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 79786823 = 2154244221 / (2 + 1 + 5 + 4 + 2 + 4 + 4 + 2 + 2 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2154244223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39893385 + ... + 39893438.

It is an arithmetic number, because the mean of its divisors is an integer number (398934120).

Almost surely, 2^2154244221 is an apocalyptic number.

It is an amenable number.

2154244221 is a deficient number, since it is larger than the sum of its proper divisors (1037228739).

2154244221 is an equidigital number, since it uses as much as digits as its factorization.

2154244221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79786832 (or 79786826 counting only the distinct ones).

The product of its digits is 5120, while the sum is 27.

The square root of 2154244221 is about 46413.8365253294. The cubic root of 2154244221 is about 1291.5116028316.

Adding to 2154244221 its reverse (1224424512), we get a palindrome (3378668733).

The spelling of 2154244221 in words is "two billion, one hundred fifty-four million, two hundred forty-four thousand, two hundred twenty-one".