51267840 has 216 divisors, whose sum is σ = 179544960. Its totient is φ = 12460032.

The previous prime is 51267817. The next prime is 51267841. The reversal of 51267840 is 4876215.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51267841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 648921 + ... + 648999.

Almost surely, 2^51267840 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 51267840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89772480).

51267840 is an abundant number, since it is smaller than the sum of its proper divisors (128277120).

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

51267840 is a wasteful number, since it uses less digits than its factorization.

51267840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 51267840 is about 7160.1564228723. The cubic root of 51267840 is about 371.4910371132.

The spelling of 51267840 in words is "fifty-one million, two hundred sixty-seven thousand, eight hundred forty".