51075640 has 192 divisors, whose sum is σ = 153653760. Its totient is φ = 15079680.

The previous prime is 51075613. The next prime is 51075643. The reversal of 51075640 is 4657015.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 51075599 and 51075608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51075643) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 495829 + ... + 495931.

It is an arithmetic number, because the mean of its divisors is an integer number (800280).

Almost surely, 2^51075640 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 51075640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76826880).

51075640 is an abundant number, since it is smaller than the sum of its proper divisors (102578120).

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

51075640 is a wasteful number, since it uses less digits than its factorization.

51075640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 51075640 is about 7146.7223256539. The cubic root of 51075640 is about 371.0262233748.

It can be divided in two parts, 51075 and 640, that added together give a palindrome (51715).

The spelling of 51075640 in words is "fifty-one million, seventy-five thousand, six hundred forty".