51254640 has 160 divisors (see below), whose sum is σ = 179899200. Its totient is φ = 13409280.

The previous prime is 51254611. The next prime is 51254663. The reversal of 51254640 is 4645215.

51254640 is a `hidden beast` number, since 5 + 12 + 5 + 4 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131566 + ... + 131954.

It is an arithmetic number, because the mean of its divisors is an integer number (1124370).

Almost surely, 2^51254640 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 51254640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89949600).

51254640 is an abundant number, since it is smaller than the sum of its proper divisors (128644560).

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

51254640 is a wasteful number, since it uses less digits than its factorization.

51254640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 51254640 is about 7159.2345959607. The cubic root of 51254640 is about 371.4591516101.

Adding to 51254640 its reverse (4645215), we get a palindrome (55899855).

The spelling of 51254640 in words is "fifty-one million, two hundred fifty-four thousand, six hundred forty".