51861855 has 16 divisors (see below), whose sum is σ = 83293920. Its totient is φ = 27554688.

The previous prime is 51861851. The next prime is 51861863. The reversal of 51861855 is 55816815.

It is not a de Polignac number, because 51861855 - 2² = 51861851 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51861851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2392 + ... + 10461.

It is an arithmetic number, because the mean of its divisors is an integer number (5205870).

Almost surely, 2^51861855 is an apocalyptic number.

51861855 is a deficient number, since it is larger than the sum of its proper divisors (31432065).

51861855 is a wasteful number, since it uses less digits than its factorization.

51861855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13130.

The product of its digits is 48000, while the sum is 39.

The square root of 51861855 is about 7201.5175484060. The cubic root of 51861855 is about 372.9202919379.

The spelling of 51861855 in words is "fifty-one million, eight hundred sixty-one thousand, eight hundred fifty-five".