51506420 has 48 divisors (see below), whose sum is σ = 125207040. Its totient is φ = 17432064.

The previous prime is 51506401. The next prime is 51506431. The reversal of 51506420 is 2460515.

It is a super-2 number, since 2×51506420² = 5305822602432800, which contains 22 as substring.

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, 8732 + ... + 13388.

It is an arithmetic number, because the mean of its divisors is an integer number (2608480).

Almost surely, 2^51506420 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 51506420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62603520).

51506420 is an abundant number, since it is smaller than the sum of its proper divisors (73700620).

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

51506420 is a wasteful number, since it uses less digits than its factorization.

51506420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4752 (or 4750 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 51506420 is about 7176.7973358595. The cubic root of 51506420 is about 372.0664023754.

Adding to 51506420 its reverse (2460515), we get a palindrome (53966935).

The spelling of 51506420 in words is "fifty-one million, five hundred six thousand, four hundred twenty".