51542239 has 4 divisors (see below), whose sum is σ = 58905424. Its totient is φ = 44179056.

The previous prime is 51542203. The next prime is 51542261. The reversal of 51542239 is 93224515.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51542239 - 2¹¹ = 51540191 is a prime.

It is a super-2 number, since 2×51542239² = 5313204802266242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51542239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51542299) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3681582 + ... + 3681595.

It is an arithmetic number, because the mean of its divisors is an integer number (14726356).

Almost surely, 2^51542239 is an apocalyptic number.

51542239 is a deficient number, since it is larger than the sum of its proper divisors (7363185).

51542239 is an equidigital number, since it uses as much as digits as its factorization.

51542239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7363184.

The product of its digits is 10800, while the sum is 31.

The square root of 51542239 is about 7179.2923746007. The cubic root of 51542239 is about 372.1526308386.

The spelling of 51542239 in words is "fifty-one million, five hundred forty-two thousand, two hundred thirty-nine".