51697297440 has 168 divisors, whose sum is σ = 183118942188. Its totient is φ = 13785914880.

The previous prime is 51697297367. The next prime is 51697297459. The reversal of 51697297440 is 4479279615.

51697297440 is a `hidden beast` number, since 51 + 69 + 7 + 2 + 97 + 440 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 42685212816 + 9012084624 = 206604^2 + 94932^2 .

It is a super-2 number, since 2×51697297440² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 104971 + ... + 338250.

Almost surely, 2^51697297440 is an apocalyptic number.

It is an amenable number.

51697297440 is an abundant number, since it is smaller than the sum of its proper divisors (131421644748).

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

51697297440 is an equidigital number, since it uses as much as digits as its factorization.

51697297440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443254 (or 443231 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 51697297440 in words is "fifty-one billion, six hundred ninety-seven million, two hundred ninety-seven thousand, four hundred forty".