51018639 has 8 divisors (see below), whose sum is σ = 77742720. Its totient is φ = 29153496.

The previous prime is 51018589. The next prime is 51018659. The reversal of 51018639 is 93681015.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51018639 - 2¹² = 51014543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51018659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1214709 + ... + 1214750.

It is an arithmetic number, because the mean of its divisors is an integer number (9717840).

Almost surely, 2^51018639 is an apocalyptic number.

51018639 is a deficient number, since it is larger than the sum of its proper divisors (26724081).

51018639 is a wasteful number, since it uses less digits than its factorization.

51018639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2429469.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 51018639 is about 7142.7333003550. The cubic root of 51018639 is about 370.8881488244. Note that the first 3 decimals are identical.

The spelling of 51018639 in words is "fifty-one million, eighteen thousand, six hundred thirty-nine".