51345840 has 160 divisors (see below), whose sum is σ = 195987456. Its totient is φ = 10828800.

The previous prime is 51345839. The next prime is 51345857. The reversal of 51345840 is 4854315.

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 = 51345798 and 51345807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20665 + ... + 23015.

Almost surely, 2^51345840 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 51345840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97993728).

51345840 is an abundant number, since it is smaller than the sum of its proper divisors (144641616).

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

51345840 is a wasteful number, since it uses less digits than its factorization.

51345840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2387 (or 2381 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

The square root of 51345840 is about 7165.6011611030. The cubic root of 51345840 is about 371.6793398142.

The spelling of 51345840 in words is "fifty-one million, three hundred forty-five thousand, eight hundred forty".