51221444 has 12 divisors (see below), whose sum is σ = 89796924. Its totient is φ = 25565184.

The previous prime is 51221441. The next prime is 51221491. The reversal of 51221444 is 44412215.

It can be written as a sum of positive squares in 2 ways, for example, as 49984900 + 1236544 = 7070^2 + 1112^2 .

It is not an unprimeable number, because it can be changed into a prime (51221441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8789 + ... + 13404.

It is an arithmetic number, because the mean of its divisors is an integer number (7483077).

Almost surely, 2^51221444 is an apocalyptic number.

It is an amenable number.

51221444 is a deficient number, since it is larger than the sum of its proper divisors (38575480).

51221444 is a wasteful number, since it uses less digits than its factorization.

51221444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22774 (or 22772 counting only the distinct ones).

The product of its digits is 1280, while the sum is 23.

The square root of 51221444 is about 7156.9158161879. The cubic root of 51221444 is about 371.3789401985.

Adding to 51221444 its reverse (44412215), we get a palindrome (95633659).

The spelling of 51221444 in words is "fifty-one million, two hundred twenty-one thousand, four hundred forty-four".