51913440 has 192 divisors, whose sum is σ = 185613120. Its totient is φ = 13547520.

The previous prime is 51913417. The next prime is 51913441. The reversal of 51913440 is 4431915.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51913441) 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, 263422 + ... + 263618.

It is an arithmetic number, because the mean of its divisors is an integer number (966735).

Almost surely, 2^51913440 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 51913440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92806560).

51913440 is an abundant number, since it is smaller than the sum of its proper divisors (133699680).

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

51913440 is a wasteful number, since it uses less digits than its factorization.

51913440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 51913440 is about 7205.0981950283. The cubic root of 51913440 is about 373.0438941413.

The spelling of 51913440 in words is "fifty-one million, nine hundred thirteen thousand, four hundred forty".