51431609 has 4 divisors (see below), whose sum is σ = 51446400. Its totient is φ = 51416820.

The previous prime is 51431563. The next prime is 51431629. The reversal of 51431609 is 90613415.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 51431609 - 2¹² = 51427513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51431629) 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, 992 + ... + 10190.

It is an arithmetic number, because the mean of its divisors is an integer number (12861600).

Almost surely, 2^51431609 is an apocalyptic number.

It is an amenable number.

51431609 is a deficient number, since it is larger than the sum of its proper divisors (14791).

51431609 is an equidigital number, since it uses as much as digits as its factorization.

51431609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14790.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 51431609 is about 7171.5834374286. The cubic root of 51431609 is about 371.8861779377.

It can be divided in two parts, 514 and 31609, that added together give a palindrome (32123).

The spelling of 51431609 in words is "fifty-one million, four hundred thirty-one thousand, six hundred nine".