51789240 has 128 divisors (see below), whose sum is σ = 175104000. Its totient is φ = 13613184.

The previous prime is 51789239. The next prime is 51789247. The reversal of 51789240 is 4298715.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51789195 and 51789204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51789247) 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, 85017 + ... + 85623.

It is an arithmetic number, because the mean of its divisors is an integer number (1368000).

Almost surely, 2^51789240 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 51789240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87552000).

51789240 is an abundant number, since it is smaller than the sum of its proper divisors (123314760).

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

51789240 is a wasteful number, since it uses less digits than its factorization.

51789240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706 (or 696 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 51789240 is about 7196.4741366867. The cubic root of 51789240 is about 372.7461610315.

The spelling of 51789240 in words is "fifty-one million, seven hundred eighty-nine thousand, two hundred forty".