51861280 has 48 divisors (see below), whose sum is σ = 126758520. Its totient is φ = 20027392.

The previous prime is 51861247. The next prime is 51861281. The reversal of 51861280 is 8216815.

It can be written as a sum of positive squares in 4 ways, for example, as 48944016 + 2917264 = 6996^2 + 1708^2 .

It is not an unprimeable number, because it can be changed into a prime (51861281) 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, 949 + ... + 10228.

Almost surely, 2^51861280 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 51861280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63379260).

51861280 is an abundant number, since it is smaller than the sum of its proper divisors (74897240).

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

51861280 is a wasteful number, since it uses less digits than its factorization.

51861280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11221 (or 11213 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 51861280 is about 7201.4776261542. The cubic root of 51861280 is about 372.9189137255.

The spelling of 51861280 in words is "fifty-one million, eight hundred sixty-one thousand, two hundred eighty".