51257340 has 96 divisors (see below), whose sum is σ = 166440960. Its totient is φ = 13071168.

The previous prime is 51257293. The next prime is 51257347. The reversal of 51257340 is 4375215.

It is a happy number.

51257340 is a `hidden beast` number, since 51 + 2 + 573 + 40 = 666.

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

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51257347) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10357 + ... + 14483.

It is an arithmetic number, because the mean of its divisors is an integer number (1733760).

Almost surely, 2^51257340 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 51257340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83220480).

51257340 is an abundant number, since it is smaller than the sum of its proper divisors (115183620).

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

51257340 is a wasteful number, since it uses less digits than its factorization.

51257340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4168 (or 4160 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 51257340 is about 7159.4231611213. The cubic root of 51257340 is about 371.4656740902.

The spelling of 51257340 in words is "fifty-one million, two hundred fifty-seven thousand, three hundred forty".