51390464 has 48 divisors (see below), whose sum is σ = 107321760. Its totient is φ = 24555520.

The previous prime is 51390433. The next prime is 51390569. The reversal of 51390464 is 46409315.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 51390464.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46559 + ... + 47649.

It is an arithmetic number, because the mean of its divisors is an integer number (2235870).

Almost surely, 2^51390464 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 51390464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53660880).

51390464 is an abundant number, since it is smaller than the sum of its proper divisors (55931296).

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

51390464 is a wasteful number, since it uses less digits than its factorization.

51390464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136 (or 1116 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 51390464 is about 7168.7142501288. The cubic root of 51390464 is about 371.7869825258.

Adding to 51390464 its reverse (46409315), we get a palindrome (97799779).

The spelling of 51390464 in words is "fifty-one million, three hundred ninety thousand, four hundred sixty-four".