51540309 has 12 divisors (see below), whose sum is σ = 77684256. Its totient is φ = 32866152.

The previous prime is 51540289. The next prime is 51540329. The reversal of 51540309 is 90304515.

It is an interprime number because it is at equal distance from previous prime (51540289) and next prime (51540329).

It is not a de Polignac number, because 51540309 - 2⁸ = 51540053 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51540329) 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, 124287 + ... + 124700.

It is an arithmetic number, because the mean of its divisors is an integer number (6473688).

Almost surely, 2^51540309 is an apocalyptic number.

It is an amenable number.

51540309 is a deficient number, since it is larger than the sum of its proper divisors (26143947).

51540309 is a wasteful number, since it uses less digits than its factorization.

51540309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249016 (or 249013 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 51540309 is about 7179.1579589810. The cubic root of 51540309 is about 372.1479856935.

The spelling of 51540309 in words is "fifty-one million, five hundred forty thousand, three hundred nine".