51209538 has 16 divisors (see below), whose sum is σ = 103716480. Its totient is φ = 16853616.

The previous prime is 51209537. The next prime is 51209539. The reversal of 51209538 is 83590215.

It is an interprime number because it is at equal distance from previous prime (51209537) and next prime (51209539).

It is a junction number, because it is equal to n+sod(n) for n = 51209499 and 51209508.

It is not an unprimeable number, because it can be changed into a prime (51209537) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 53545 + ... + 54492.

It is an arithmetic number, because the mean of its divisors is an integer number (6482280).

Almost surely, 2^51209538 is an apocalyptic number.

51209538 is an abundant number, since it is smaller than the sum of its proper divisors (52506942).

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

51209538 is a wasteful number, since it uses less digits than its factorization.

51209538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108121.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 51209538 is about 7156.0839849739. The cubic root of 51209538 is about 371.3501633169.

The spelling of 51209538 in words is "fifty-one million, two hundred nine thousand, five hundred thirty-eight".