51637440 has 168 divisors, whose sum is σ = 174193200. Its totient is φ = 12957696.

The previous prime is 51637433. The next prime is 51637447. The reversal of 51637440 is 4473615.

It is an interprime number because it is at equal distance from previous prime (51637433) and next prime (51637447).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51637398 and 51637407.

It is not an unprimeable number, because it can be changed into a prime (51637447) 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, 346486 + ... + 346634.

Almost surely, 2^51637440 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 51637440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87096600).

51637440 is an abundant number, since it is smaller than the sum of its proper divisors (122555760).

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

51637440 is a wasteful number, since it uses less digits than its factorization.

51637440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 51637440 is about 7185.9195653723. The cubic root of 51637440 is about 372.3816178626.

The spelling of 51637440 in words is "fifty-one million, six hundred thirty-seven thousand, four hundred forty".