51320400440 has 32 divisors (see below), whose sum is σ = 117363872160. Its totient is φ = 20191632000.

The previous prime is 51320400353. The next prime is 51320400491. The reversal of 51320400440 is 4400402315.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10514036 + ... + 10518915.

It is an arithmetic number, because the mean of its divisors is an integer number (3667621005).

Almost surely, 2^51320400440 is an apocalyptic number.

It is an amenable number.

51320400440 is an abundant number, since it is smaller than the sum of its proper divisors (66043471720).

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

51320400440 is a wasteful number, since it uses less digits than its factorization.

51320400440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21033023 (or 21033019 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

Adding to 51320400440 its reverse (4400402315), we get a palindrome (55720802755).

The spelling of 51320400440 in words is "fifty-one billion, three hundred twenty million, four hundred thousand, four hundred forty".