51550139 has 16 divisors (see below), whose sum is σ = 55404000. Its totient is φ = 47867904.

The previous prime is 51550099. The next prime is 51550159. The reversal of 51550139 is 93105515.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 51550139 - 2¹² = 51546043 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51550159) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114587 + ... + 115035.

It is an arithmetic number, because the mean of its divisors is an integer number (3462750).

Almost surely, 2^51550139 is an apocalyptic number.

51550139 is a deficient number, since it is larger than the sum of its proper divisors (3853861).

51550139 is a wasteful number, since it uses less digits than its factorization.

51550139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622.

The product of its (nonzero) digits is 3375, while the sum is 29.

The square root of 51550139 is about 7179.8425470201. The cubic root of 51550139 is about 372.1716434365.

The spelling of 51550139 in words is "fifty-one million, five hundred fifty thousand, one hundred thirty-nine".