51511224 has 64 divisors (see below), whose sum is σ = 137168640. Its totient is φ = 16064000.

The previous prime is 51511217. The next prime is 51511247. The reversal of 51511224 is 42211515.

It is a self number, because there is not a number n which added to its sum of digits gives 51511224.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102157 + ... + 102659.

It is an arithmetic number, because the mean of its divisors is an integer number (2143260).

Almost surely, 2^51511224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51511224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68584320).

51511224 is an abundant number, since it is smaller than the sum of its proper divisors (85657416).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51511224 is a wasteful number, since it uses less digits than its factorization.

51511224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780 (or 776 counting only the distinct ones).

The product of its digits is 400, while the sum is 21.

The square root of 51511224 is about 7177.1320177352. The cubic root of 51511224 is about 372.0779695511.

Adding to 51511224 its reverse (42211515), we get a palindrome (93722739).

The spelling of 51511224 in words is "fifty-one million, five hundred eleven thousand, two hundred twenty-four".