51420309 has 4 divisors (see below), whose sum is σ = 68560416. Its totient is φ = 34280204.

The previous prime is 51420307. The next prime is 51420319. The reversal of 51420309 is 90302415.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51420309 - 2¹ = 51420307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51420301) 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 3 ways as a sum of consecutive naturals, for example, 8570049 + ... + 8570054.

It is an arithmetic number, because the mean of its divisors is an integer number (17140104).

Almost surely, 2^51420309 is an apocalyptic number.

It is an amenable number.

51420309 is a deficient number, since it is larger than the sum of its proper divisors (17140107).

51420309 is a wasteful number, since it uses less digits than its factorization.

51420309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17140106.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 51420309 is about 7170.7955625579. The cubic root of 51420309 is about 371.8589403323.

The spelling of 51420309 in words is "fifty-one million, four hundred twenty thousand, three hundred nine".