51381309 has 16 divisors (see below), whose sum is σ = 78825600. Its totient is φ = 29161920.

The previous prime is 51381299. The next prime is 51381313. The reversal of 51381309 is 90318315.

It is a happy number.

It is not a de Polignac number, because 51381309 - 2⁸ = 51381053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51381509) 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, 5082 + ... + 11339.

It is an arithmetic number, because the mean of its divisors is an integer number (4926600).

Almost surely, 2^51381309 is an apocalyptic number.

It is an amenable number.

51381309 is a deficient number, since it is larger than the sum of its proper divisors (27444291).

51381309 is a wasteful number, since it uses less digits than its factorization.

51381309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16580.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 51381309 is about 7168.0756831942. The cubic root of 51381309 is about 371.7649037736.

The spelling of 51381309 in words is "fifty-one million, three hundred eighty-one thousand, three hundred nine".