51442709 has 4 divisors (see below), whose sum is σ = 54150240. Its totient is φ = 48735180.

The previous prime is 51442681. The next prime is 51442717. The reversal of 51442709 is 90724415.

It is a happy number.

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 an emirpimes, since its reverse is a distinct semiprime: 90724415 = 5 ⋅18144883.

It is a cyclic number.

It is not a de Polignac number, because 51442709 - 2⁸ = 51442453 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 (51442739) 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, 1353737 + ... + 1353774.

It is an arithmetic number, because the mean of its divisors is an integer number (13537560).

Almost surely, 2^51442709 is an apocalyptic number.

It is an amenable number.

51442709 is a deficient number, since it is larger than the sum of its proper divisors (2707531).

51442709 is a wasteful number, since it uses less digits than its factorization.

51442709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2707530.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 51442709 is about 7172.3572833483. The cubic root of 51442709 is about 371.9129295775.

The spelling of 51442709 in words is "fifty-one million, four hundred forty-two thousand, seven hundred nine".