51391200 has 432 divisors, whose sum is σ = 213736320. Its totient is φ = 10644480.

The previous prime is 51391199. The next prime is 51391201. The reversal of 51391200 is 219315.

It is an interprime number because it is at equal distance from previous prime (51391199) and next prime (51391201).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51391201) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2234389 + ... + 2234411.

It is an arithmetic number, because the mean of its divisors is an integer number (494760).

Almost surely, 2^51391200 is an apocalyptic number.

51391200 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51391200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106868160).

51391200 is an abundant number, since it is smaller than the sum of its proper divisors (162345120).

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

51391200 is a wasteful number, since it uses less digits than its factorization.

51391200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 51391200 is about 7168.7655841156. The cubic root of 51391200 is about 371.7887573941.

It can be divided in two parts, 513 and 91200, that multiplied together give a square (46785600 = 6840²).

The spelling of 51391200 in words is "fifty-one million, three hundred ninety-one thousand, two hundred".