51481644 has 48 divisors (see below), whose sum is σ = 128969568. Its totient is φ = 15925248.

The previous prime is 51481643. The next prime is 51481667. The reversal of 51481644 is 44618415.

It is not an unprimeable number, because it can be changed into a prime (51481643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13164 + ... + 16620.

It is an arithmetic number, because the mean of its divisors is an integer number (2686866).

Almost surely, 2^51481644 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 51481644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64484784).

51481644 is an abundant number, since it is smaller than the sum of its proper divisors (77487924).

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

51481644 is a wasteful number, since it uses less digits than its factorization.

51481644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3554 (or 3552 counting only the distinct ones).

The product of its digits is 15360, while the sum is 33.

The square root of 51481644 is about 7175.0710101016. The cubic root of 51481644 is about 372.0067347607.

It can be divided in two parts, 51481 and 644, that added together give a palindrome (52125).

The spelling of 51481644 in words is "fifty-one million, four hundred eighty-one thousand, six hundred forty-four".