51817428 has 144 divisors (see below), whose sum is σ = 154949760. Its totient is φ = 14916096.

The previous prime is 51817421. The next prime is 51817429. The reversal of 51817428 is 82471815.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51817392 and 51817401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51817421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 310201 + ... + 310367.

It is an arithmetic number, because the mean of its divisors is an integer number (1076040).

Almost surely, 2^51817428 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 51817428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77474880).

51817428 is an abundant number, since it is smaller than the sum of its proper divisors (103132332).

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

51817428 is a wasteful number, since it uses less digits than its factorization.

51817428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 202 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 51817428 is about 7198.4323293339. The cubic root of 51817428 is about 372.8137752252.

The spelling of 51817428 in words is "fifty-one million, eight hundred seventeen thousand, four hundred twenty-eight".