51005500420 has 36 divisors (see below), whose sum is σ = 124599153420. Its totient is φ = 17487599808.

The previous prime is 51005500409. The next prime is 51005500423. The reversal of 51005500420 is 2400550015.

It can be written as a sum of positive squares in 2 ways, for example, as 37929120516 + 13076379904 = 194754^2 + 114352^2 .

It is a super-2 number, since 2×51005500420² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51005500391 and 51005500400.

It is not an unprimeable number, because it can be changed into a prime (51005500423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26022235 + ... + 26024194.

It is an arithmetic number, because the mean of its divisors is an integer number (3461087595).

Almost surely, 2^51005500420 is an apocalyptic number.

It is an amenable number.

51005500420 is an abundant number, since it is smaller than the sum of its proper divisors (73593653000).

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

51005500420 is a wasteful number, since it uses less digits than its factorization.

51005500420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52046452 (or 52046443 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 22.

The spelling of 51005500420 in words is "fifty-one billion, five million, five hundred thousand, four hundred twenty".