51861847 has 4 divisors (see below), whose sum is σ = 52270336. Its totient is φ = 51453360.

The previous prime is 51861833. The next prime is 51861851. The reversal of 51861847 is 74816815.

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 51861847 - 2¹⁵ = 51829079 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 (51861877) 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, 204054 + ... + 204307.

It is an arithmetic number, because the mean of its divisors is an integer number (13067584).

Almost surely, 2^51861847 is an apocalyptic number.

51861847 is a deficient number, since it is larger than the sum of its proper divisors (408489).

51861847 is a wasteful number, since it uses less digits than its factorization.

51861847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408488.

The product of its digits is 53760, while the sum is 40.

The square root of 51861847 is about 7201.5169929675. The cubic root of 51861847 is about 372.9202727628.

The spelling of 51861847 in words is "fifty-one million, eight hundred sixty-one thousand, eight hundred forty-seven".