51869440 has 108 divisors (see below), whose sum is σ = 144702936. Its totient is φ = 17762304.

The previous prime is 51869423. The next prime is 51869443. The reversal of 51869440 is 4496815.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 51869440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51869443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62307 + ... + 63133.

It is an arithmetic number, because the mean of its divisors is an integer number (1339842).

Almost surely, 2^51869440 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 51869440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72351468).

51869440 is an abundant number, since it is smaller than the sum of its proper divisors (92833496).

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

51869440 is an equidigital number, since it uses as much as digits as its factorization.

51869440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862 (or 841 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 51869440 is about 7202.0441542662. The cubic root of 51869440 is about 372.9384714041.

The spelling of 51869440 in words is "fifty-one million, eight hundred sixty-nine thousand, four hundred forty".