51388309 has 12 divisors (see below), whose sum is σ = 60624288. Its totient is φ = 43423800.

The previous prime is 51388307. The next prime is 51388327. The reversal of 51388309 is 90388315.

It is not a de Polignac number, because 51388309 - 2¹ = 51388307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51388303) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3907 + ... + 10864.

It is an arithmetic number, because the mean of its divisors is an integer number (5052024).

Almost surely, 2^51388309 is an apocalyptic number.

It is an amenable number.

51388309 is a deficient number, since it is larger than the sum of its proper divisors (9235979).

51388309 is a wasteful number, since it uses less digits than its factorization.

51388309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14856 (or 14849 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 51388309 is about 7168.5639426596. The cubic root of 51388309 is about 371.7817856333.

The spelling of 51388309 in words is "fifty-one million, three hundred eighty-eight thousand, three hundred nine".