51431328 has 192 divisors, whose sum is σ = 170755200. Its totient is φ = 14929920.

The previous prime is 51431327. The next prime is 51431329. The reversal of 51431328 is 82313415.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51431327) and next prime (51431329).

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

It is not an unprimeable number, because it can be changed into a prime (51431327) 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, 213288 + ... + 213528.

It is an arithmetic number, because the mean of its divisors is an integer number (889350).

Almost surely, 2^51431328 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 51431328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85377600).

51431328 is an abundant number, since it is smaller than the sum of its proper divisors (119323872).

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

51431328 is a wasteful number, since it uses less digits than its factorization.

51431328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 278 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 51431328 is about 7171.5638461914. The cubic root of 51431328 is about 371.8855006615.

The spelling of 51431328 in words is "fifty-one million, four hundred thirty-one thousand, three hundred twenty-eight".